From a0e1cfc0683ed768a5d84e31562aeebf2e30acef Mon Sep 17 00:00:00 2001
From: James Garbutt <43081j@users.noreply.github.com>
Date: Mon, 20 Jul 2026 15:37:29 +0100
Subject: [PATCH 1/3] perf: pre-compute instance init functions

When we construct a row, we iterate over the table's features and
initialise any which have an `initRowInstanceData`.

This is expensive since most don't have such a method.

We actually know when we construct the table which features have this
method. This changes the table construction to store the initialisers up
front so when we create a row, we can just iterate the already known
initialisers.
---
 packages/table-core/src/core/rows/constructRow.ts      |  6 +++---
 packages/table-core/src/core/table/constructTable.ts   | 10 ++++++++++
 .../src/core/table/coreTablesFeature.types.ts          |  5 +++++
 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/packages/table-core/src/core/rows/constructRow.ts b/packages/table-core/src/core/rows/constructRow.ts
index 663f346962..a950f00505 100644
--- a/packages/table-core/src/core/rows/constructRow.ts
+++ b/packages/table-core/src/core/rows/constructRow.ts
@@ -59,9 +59,9 @@ export const constructRow = <
   row.subRows = subRows ?? []
 
   // Initialize instance-specific data (e.g., caches) for features that need it
-  const features = Object.values(table._features)
-  for (let i = 0; i < features.length; i++) {
-    features[i]!.initRowInstanceData?.(row)
+  const initFns = table._rowInstanceInitFns!
+  for (let i = 0; i < initFns.length; i++) {
+    initFns[i]!(row as Row<TFeatures, TData>)
   }
 
   return row as Row<TFeatures, TData>
diff --git a/packages/table-core/src/core/table/constructTable.ts b/packages/table-core/src/core/table/constructTable.ts
index 3a2f648966..520a33303a 100644
--- a/packages/table-core/src/core/table/constructTable.ts
+++ b/packages/table-core/src/core/table/constructTable.ts
@@ -68,6 +68,16 @@ export function constructTable<
 
   const featuresList: Array<TableFeature> = Object.values(table._features)
 
+  const rowInstanceInitFns: Array<
+    NonNullable<TableFeature['initRowInstanceData']>
+  > = []
+  for (const feature of featuresList) {
+    if (feature.initRowInstanceData) {
+      rowInstanceInitFns.push(feature.initRowInstanceData)
+    }
+  }
+  table._rowInstanceInitFns = rowInstanceInitFns
+
   const defaultOptions = featuresList.reduce((obj, feature) => {
     return Object.assign(obj, feature.getDefaultTableOptions?.(table))
   }, {}) as TableOptions<TFeatures, TData>
diff --git a/packages/table-core/src/core/table/coreTablesFeature.types.ts b/packages/table-core/src/core/table/coreTablesFeature.types.ts
index 8570660430..80afe099e7 100644
--- a/packages/table-core/src/core/table/coreTablesFeature.types.ts
+++ b/packages/table-core/src/core/table/coreTablesFeature.types.ts
@@ -5,6 +5,7 @@ import type { RowModelFns } from '../../types/RowModelFns'
 import type { RowData, Updater } from '../../types/type-utils'
 import type {
   IsAny,
+  TableFeature,
   TableFeatures,
   ValidateFeatureSlots,
 } from '../../types/TableFeatures'
@@ -188,6 +189,10 @@ export interface Table_CoreProperties<
    * Prototype cache for Row objects - shared by all rows in this table
    */
   _rowPrototype?: object
+  /**
+   * Cache of the `initRowInstanceData` functions for features that define one.
+   */
+  _rowInstanceInitFns?: Array<NonNullable<TableFeature['initRowInstanceData']>>
   /**
    * The readonly derived atoms for each `TableState` slice. Each derives from
    * its corresponding `baseAtom` plus, optionally, a per-slice external atom or

From a0057d30a2c1f0a07c4a7bafe160c07276cc9c30 Mon Sep 17 00:00:00 2001
From: James Garbutt <43081j@users.noreply.github.com>
Date: Mon, 20 Jul 2026 16:10:40 +0100
Subject: [PATCH 2/3] fix(table-core): bind initialiser to feature

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>
---
 packages/table-core/src/core/table/constructTable.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/table-core/src/core/table/constructTable.ts b/packages/table-core/src/core/table/constructTable.ts
index 520a33303a..2d706c8234 100644
--- a/packages/table-core/src/core/table/constructTable.ts
+++ b/packages/table-core/src/core/table/constructTable.ts
@@ -73,7 +73,7 @@ export function constructTable<
   > = []
   for (const feature of featuresList) {
     if (feature.initRowInstanceData) {
-      rowInstanceInitFns.push(feature.initRowInstanceData)
+      rowInstanceInitFns.push(feature.initRowInstanceData.bind(feature))
     }
   }
   table._rowInstanceInitFns = rowInstanceInitFns

From 7f6d788c5aa56dfd94c56c4b203b99fedd292492 Mon Sep 17 00:00:00 2001
From: Kevin Van Cott <kevinvandy656@gmail.com>
Date: Fri, 24 Jul 2026 10:57:30 -0500
Subject: [PATCH 3/3] cache init functions consistently for all table objects

---
 .../framework/alpine/guide/custom-features.md |  50 +++-
 .../angular/guide/custom-features.md          |  50 +++-
 docs/framework/ember/guide/custom-features.md |  50 +++-
 docs/framework/lit/guide/custom-features.md   |  50 +++-
 .../framework/preact/guide/custom-features.md |  50 +++-
 docs/framework/react/guide/custom-features.md |  50 +++-
 docs/framework/solid/guide/custom-features.md |  50 +++-
 .../framework/svelte/guide/custom-features.md |  50 +++-
 docs/framework/vue/guide/custom-features.md   |  50 +++-
 .../index/functions/constructColumn.md        |   2 +-
 .../index/functions/makeStateUpdater.md       |   2 +-
 .../index/interfaces/ColumnDef_RowSorting.md  |   2 +-
 .../index/interfaces/FeatureSlotPrereqs.md    |  30 +--
 docs/reference/index/interfaces/Plugins.md    |   2 +-
 .../index/interfaces/Row_Aggregation.md       |   6 +-
 .../index/interfaces/TableFeature.md          | 154 ++++++++++--
 .../index/interfaces/TableFeatures.md         |  32 +--
 docs/reference/index/interfaces/TableMeta.md  |   2 +-
 .../index/interfaces/TableOptions_Core.md     |  18 +-
 .../index/interfaces/TableOptions_Table.md    |  20 +-
 docs/reference/index/interfaces/Table_Core.md | 224 +++++++++++++++--
 .../index/interfaces/Table_CoreProperties.md  | 202 ++++++++++++++--
 .../index/interfaces/Table_Internal.md        | 220 ++++++++++++++++-
 .../reference/index/interfaces/Table_Table.md | 226 ++++++++++++++++--
 docs/reference/index/type-aliases/Atoms.md    |   2 +-
 .../reference/index/type-aliases/Atoms_All.md |   2 +-
 .../reference/index/type-aliases/BaseAtoms.md |   2 +-
 .../index/type-aliases/BaseAtoms_All.md       |   2 +-
 .../type-aliases/BuiltInAggregationFn.md      |   2 +-
 .../index/type-aliases/ColumnDefResolved.md   |   2 +-
 .../reference/index/type-aliases/DeepValue.md |   2 +-
 .../index/type-aliases/ExternalAtoms.md       |   2 +-
 .../index/type-aliases/ExternalAtoms_All.md   |   2 +-
 .../type-aliases/ExtractFeatureMapTypes.md    |   2 +-
 .../index/type-aliases/ExtractTableMeta.md    |   2 +-
 docs/reference/index/type-aliases/IsAny.md    |   2 +-
 .../index/type-aliases/NonFeatureKeys.md      |   2 +-
 .../type-aliases/ValidateFeatureSlots.md      |   2 +-
 .../index/variables/aggregationFn_count.md    |   2 +-
 .../index/variables/aggregationFn_extent.md   |   2 +-
 .../index/variables/aggregationFn_first.md    |   2 +-
 .../index/variables/aggregationFn_last.md     |   2 +-
 .../index/variables/aggregationFn_max.md      |   2 +-
 .../index/variables/aggregationFn_mean.md     |   2 +-
 .../index/variables/aggregationFn_median.md   |   2 +-
 .../index/variables/aggregationFn_min.md      |   2 +-
 .../index/variables/aggregationFn_sum.md      |   2 +-
 .../index/variables/aggregationFn_unique.md   |   2 +-
 .../variables/aggregationFn_uniqueCount.md    |   2 +-
 .../index/variables/aggregationFns.md         |   2 +-
 .../functions/aggregateColumnValue.md         |  10 +-
 .../functions/cell_getIsAggregated.md         |   2 +-
 .../functions/column_getAggregationFns.md     |   2 +-
 .../functions/column_getAggregationValue.md   |   2 +-
 .../functions/column_getAutoAggregationFn.md  |   2 +-
 .../functions/formatAggregatedCellValue.md    |   2 +-
 .../functions/isRowSelected.md                |   2 +-
 .../functions/isSubRowSelected.md             |   2 +-
 .../normalizeUniqueAggregationRows.md         |  42 ++++
 .../functions/row_getCanMultiSelect.md        |   2 +-
 .../functions/row_getCanSelect.md             |   2 +-
 .../functions/row_getCanSelectSubRows.md      |   2 +-
 .../functions/row_getIsAllSubRowsSelected.md  |   2 +-
 .../functions/row_getIsSelected.md            |   2 +-
 .../functions/row_getIsSomeSelected.md        |   2 +-
 .../functions/row_getToggleSelectedHandler.md |   2 +-
 .../functions/row_toggleSelected.md           |   5 +-
 .../functions/selectRowsFn.md                 |   2 +-
 docs/reference/static-functions/index.md      |   1 +
 .../src/core/cells/constructCell.ts           |   6 +
 .../src/core/columns/constructColumn.ts       |   7 +-
 .../src/core/headers/buildHeaderGroups.ts     |   7 +
 .../src/core/headers/constructHeader.ts       |   6 +
 .../src/core/table/constructTable.ts          |  53 +++-
 .../src/core/table/coreTablesFeature.types.ts |  24 ++
 .../table-core/src/types/TableFeatures.ts     |  56 ++++-
 .../unit/core/cells/constructCell.test.ts     |  44 ++++
 .../unit/core/headers/constructHeader.test.ts | 116 +++++++++
 .../unit/core/table/constructTable.test.ts    |  53 ++++
 79 files changed, 1859 insertions(+), 245 deletions(-)
 create mode 100644 docs/reference/static-functions/functions/normalizeUniqueAggregationRows.md

diff --git a/docs/framework/alpine/guide/custom-features.md b/docs/framework/alpine/guide/custom-features.md
index b1a3dbbccf..5d0ad25fcd 100644
--- a/docs/framework/alpine/guide/custom-features.md
+++ b/docs/framework/alpine/guide/custom-features.md
@@ -70,6 +70,33 @@ export interface TableFeature {
     table: Table_Internal<TFeatures, TData>,
   ) => Partial<TableOptions_All<TFeatures, TData>>
   getInitialState?: (initialState: Partial<TableState_All>) => TableState_All
+  initCellInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    cell: Cell<TFeatures, TData, TValue>,
+  ) => void
+  initColumnInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    column: Column<TFeatures, TData, TValue>,
+  ) => void
+  initHeaderGroupInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+  >(
+    headerGroup: HeaderGroup<TFeatures, TData>,
+  ) => void
+  initHeaderInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    header: Header<TFeatures, TData, TValue>,
+  ) => void
   initRowInstanceData?: <
     TFeatures extends TableFeatures,
     TData extends RowData,
@@ -127,15 +154,21 @@ The `constructTableAPIs` method in a table feature is exclusively responsible fo
 
 <br />
 
-#### assignHeaderPrototype
+#### assignHeaderPrototype and initHeaderInstanceData
+
+The `assignHeaderPrototype` method in a table feature is responsible for adding methods to the shared `header` prototype. For example, the [Column Sizing](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/column-sizing/columnSizingFeature.ts) feature adds header instance API methods such as `getStart`. So then, when you call `header.getStart()`, you are calling a method that was added by the column sizing feature. The `initHeaderInstanceData` method is available for per-header instance data or caches that cannot live on the shared prototype. It runs during header construction, before sub-headers are populated and before the header is linked to its header group. Headers are reconstructed whenever header groups recompute, so it reruns on every rebuild.
+
+<br />
+
+#### initHeaderGroupInstanceData
 
-The `assignHeaderPrototype` method in a table feature is responsible for adding methods to the shared `header` prototype. For example, the [Column Sizing](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/column-sizing/columnSizingFeature.ts) feature adds header instance API methods such as `getStart`. So then, when you call `header.getStart()`, you are calling a method that was added by the column sizing feature.
+The `initHeaderGroupInstanceData` method is available for per-header-group instance data. Header groups have no shared prototype, so this is their only per-instance extension point. It runs after a header group's `depth`, `id`, and fully populated `headers` array have been assigned, and reruns whenever header groups are rebuilt.
 
 <br />
 
-#### assignColumnPrototype
+#### assignColumnPrototype and initColumnInstanceData
 
-The `assignColumnPrototype` method in a table feature is responsible for adding methods to the shared `column` prototype. For example, the [Sorting](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-sorting/rowSortingFeature.ts) feature adds column instance API methods such as `getNextSortingOrder`, `toggleSorting`, etc. So then, when you call `column.toggleSorting()`, you are calling a method that was added by the row sorting feature.
+The `assignColumnPrototype` method in a table feature is responsible for adding methods to the shared `column` prototype. For example, the [Sorting](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-sorting/rowSortingFeature.ts) feature adds column instance API methods such as `getNextSortingOrder`, `toggleSorting`, etc. So then, when you call `column.toggleSorting()`, you are calling a method that was added by the row sorting feature. The `initColumnInstanceData` method is available for per-column instance data or caches that cannot live on the shared prototype. For example, the [Aggregation](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-aggregation/rowAggregationFeature.ts) feature uses it to set up a per-column aggregation cache.
 
 <br />
 
@@ -145,9 +178,9 @@ The `assignRowPrototype` method in a table feature is responsible for adding met
 
 <br />
 
-#### assignCellPrototype
+#### assignCellPrototype and initCellInstanceData
 
-The `assignCellPrototype` method in a table feature is responsible for adding methods to the shared `cell` prototype. For example, Column Grouping adds `getIsGrouped` and `getIsPlaceholder`, while Aggregation adds `getIsAggregated`.
+The `assignCellPrototype` method in a table feature is responsible for adding methods to the shared `cell` prototype. For example, Column Grouping adds `getIsGrouped` and `getIsPlaceholder`, while Aggregation adds `getIsAggregated`. The `initCellInstanceData` method is available for per-cell instance data or caches that cannot live on the shared prototype. Cells are constructed lazily on first access per row/column pair and cached, so it runs once per cell instance.
 
 ## Adding a Custom Feature
 
@@ -279,10 +312,15 @@ export const densityPlugin: TableFeature = {
   // initRowInstanceData: (row) => {},
   // if you need to add cell instance APIs...
   // assignCellPrototype: (prototype, table) => {},
+  // initCellInstanceData: (cell) => {},
   // if you need to add column instance APIs...
   // assignColumnPrototype: (prototype, table) => {},
+  // initColumnInstanceData: (column) => {},
   // if you need to add header instance APIs...
   // assignHeaderPrototype: (prototype, table) => {},
+  // initHeaderInstanceData: (header) => {},
+  // if you need to add header group instance data...
+  // initHeaderGroupInstanceData: (headerGroup) => {},
 }
 ```
 
diff --git a/docs/framework/angular/guide/custom-features.md b/docs/framework/angular/guide/custom-features.md
index 19dd97dc60..50d1fe2e27 100644
--- a/docs/framework/angular/guide/custom-features.md
+++ b/docs/framework/angular/guide/custom-features.md
@@ -76,6 +76,33 @@ export interface TableFeature {
     table: Table_Internal<TFeatures, TData>,
   ) => Partial<TableOptions_All<TFeatures, TData>>
   getInitialState?: (initialState: Partial<TableState_All>) => TableState_All
+  initCellInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    cell: Cell<TFeatures, TData, TValue>,
+  ) => void
+  initColumnInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    column: Column<TFeatures, TData, TValue>,
+  ) => void
+  initHeaderGroupInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+  >(
+    headerGroup: HeaderGroup<TFeatures, TData>,
+  ) => void
+  initHeaderInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    header: Header<TFeatures, TData, TValue>,
+  ) => void
   initRowInstanceData?: <
     TFeatures extends TableFeatures,
     TData extends RowData,
@@ -133,15 +160,21 @@ The `constructTableAPIs` method in a table feature is exclusively responsible fo
 
 <br />
 
-##### assignHeaderPrototype
+##### assignHeaderPrototype and initHeaderInstanceData
+
+The `assignHeaderPrototype` method in a table feature is responsible for adding methods to the shared `header` prototype. For example, the [Column Sizing](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/column-sizing/columnSizingFeature.ts) feature adds header instance API methods such as `getStart`. So then, when you call `header.getStart()`, you are calling a method that was added by the column sizing feature. The `initHeaderInstanceData` method is available for per-header instance data or caches that cannot live on the shared prototype. It runs during header construction, before sub-headers are populated and before the header is linked to its header group. Headers are reconstructed whenever header groups recompute, so it reruns on every rebuild.
+
+<br />
+
+##### initHeaderGroupInstanceData
 
-The `assignHeaderPrototype` method in a table feature is responsible for adding methods to the shared `header` prototype. For example, the [Column Sizing](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/column-sizing/columnSizingFeature.ts) feature adds header instance API methods such as `getStart`. So then, when you call `header.getStart()`, you are calling a method that was added by the column sizing feature.
+The `initHeaderGroupInstanceData` method is available for per-header-group instance data. Header groups have no shared prototype, so this is their only per-instance extension point. It runs after a header group's `depth`, `id`, and fully populated `headers` array have been assigned, and reruns whenever header groups are rebuilt.
 
 <br />
 
-##### assignColumnPrototype
+##### assignColumnPrototype and initColumnInstanceData
 
-The `assignColumnPrototype` method in a table feature is responsible for adding methods to the shared `column` prototype. For example, the [Sorting](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-sorting/rowSortingFeature.ts) feature adds column instance API methods such as `getNextSortingOrder`, `toggleSorting`, etc. So then, when you call `column.toggleSorting()`, you are calling a method that was added by the row sorting feature.
+The `assignColumnPrototype` method in a table feature is responsible for adding methods to the shared `column` prototype. For example, the [Sorting](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-sorting/rowSortingFeature.ts) feature adds column instance API methods such as `getNextSortingOrder`, `toggleSorting`, etc. So then, when you call `column.toggleSorting()`, you are calling a method that was added by the row sorting feature. The `initColumnInstanceData` method is available for per-column instance data or caches that cannot live on the shared prototype. For example, the [Aggregation](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-aggregation/rowAggregationFeature.ts) feature uses it to set up a per-column aggregation cache.
 
 <br />
 
@@ -151,9 +184,9 @@ The `assignRowPrototype` method in a table feature is responsible for adding met
 
 <br />
 
-##### assignCellPrototype
+##### assignCellPrototype and initCellInstanceData
 
-The `assignCellPrototype` method in a table feature is responsible for adding methods to the shared `cell` prototype. For example, Column Grouping adds `getIsGrouped` and `getIsPlaceholder`, while Aggregation adds `getIsAggregated`.
+The `assignCellPrototype` method in a table feature is responsible for adding methods to the shared `cell` prototype. For example, Column Grouping adds `getIsGrouped` and `getIsPlaceholder`, while Aggregation adds `getIsAggregated`. The `initCellInstanceData` method is available for per-cell instance data or caches that cannot live on the shared prototype. Cells are constructed lazily on first access per row/column pair and cached, so it runs once per cell instance.
 
 ### Adding a Custom Feature
 
@@ -274,10 +307,15 @@ export const densityPlugin: TableFeature = {
   // initRowInstanceData: (row) => {},
   // if you need to add cell instance APIs...
   // assignCellPrototype: (prototype, table) => {},
+  // initCellInstanceData: (cell) => {},
   // if you need to add column instance APIs...
   // assignColumnPrototype: (prototype, table) => {},
+  // initColumnInstanceData: (column) => {},
   // if you need to add header instance APIs...
   // assignHeaderPrototype: (prototype, table) => {},
+  // initHeaderInstanceData: (header) => {},
+  // if you need to add header group instance data...
+  // initHeaderGroupInstanceData: (headerGroup) => {},
 }
 ```
 
diff --git a/docs/framework/ember/guide/custom-features.md b/docs/framework/ember/guide/custom-features.md
index 1f58c552b9..e303d4b6dc 100644
--- a/docs/framework/ember/guide/custom-features.md
+++ b/docs/framework/ember/guide/custom-features.md
@@ -76,6 +76,33 @@ export interface TableFeature {
     table: Table_Internal<TFeatures, TData>,
   ) => Partial<TableOptions_All<TFeatures, TData>>
   getInitialState?: (initialState: Partial<TableState_All>) => TableState_All
+  initCellInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    cell: Cell<TFeatures, TData, TValue>,
+  ) => void
+  initColumnInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    column: Column<TFeatures, TData, TValue>,
+  ) => void
+  initHeaderGroupInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+  >(
+    headerGroup: HeaderGroup<TFeatures, TData>,
+  ) => void
+  initHeaderInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    header: Header<TFeatures, TData, TValue>,
+  ) => void
   initRowInstanceData?: <
     TFeatures extends TableFeatures,
     TData extends RowData,
@@ -133,15 +160,21 @@ The `constructTableAPIs` method in a table feature is exclusively responsible fo
 
 <br />
 
-##### assignHeaderPrototype
+##### assignHeaderPrototype and initHeaderInstanceData
+
+The `assignHeaderPrototype` method in a table feature is responsible for adding methods to the shared `header` prototype. For example, the [Column Sizing](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/column-sizing/columnSizingFeature.ts) feature adds header instance API methods such as `getStart`. So then, when you call `header.getStart()`, you are calling a method that was added by the column sizing feature. The `initHeaderInstanceData` method is available for per-header instance data or caches that cannot live on the shared prototype. It runs during header construction, before sub-headers are populated and before the header is linked to its header group. Headers are reconstructed whenever header groups recompute, so it reruns on every rebuild.
+
+<br />
+
+##### initHeaderGroupInstanceData
 
-The `assignHeaderPrototype` method in a table feature is responsible for adding methods to the shared `header` prototype. For example, the [Column Sizing](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/column-sizing/columnSizingFeature.ts) feature adds header instance API methods such as `getStart`. So then, when you call `header.getStart()`, you are calling a method that was added by the column sizing feature.
+The `initHeaderGroupInstanceData` method is available for per-header-group instance data. Header groups have no shared prototype, so this is their only per-instance extension point. It runs after a header group's `depth`, `id`, and fully populated `headers` array have been assigned, and reruns whenever header groups are rebuilt.
 
 <br />
 
-##### assignColumnPrototype
+##### assignColumnPrototype and initColumnInstanceData
 
-The `assignColumnPrototype` method in a table feature is responsible for adding methods to the shared `column` prototype. For example, the [Sorting](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-sorting/rowSortingFeature.ts) feature adds column instance API methods such as `getNextSortingOrder`, `toggleSorting`, etc. So then, when you call `column.toggleSorting()`, you are calling a method that was added by the row sorting feature.
+The `assignColumnPrototype` method in a table feature is responsible for adding methods to the shared `column` prototype. For example, the [Sorting](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-sorting/rowSortingFeature.ts) feature adds column instance API methods such as `getNextSortingOrder`, `toggleSorting`, etc. So then, when you call `column.toggleSorting()`, you are calling a method that was added by the row sorting feature. The `initColumnInstanceData` method is available for per-column instance data or caches that cannot live on the shared prototype. For example, the [Aggregation](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-aggregation/rowAggregationFeature.ts) feature uses it to set up a per-column aggregation cache.
 
 <br />
 
@@ -151,9 +184,9 @@ The `assignRowPrototype` method in a table feature is responsible for adding met
 
 <br />
 
-##### assignCellPrototype
+##### assignCellPrototype and initCellInstanceData
 
-The `assignCellPrototype` method in a table feature is responsible for adding methods to the shared `cell` prototype. For example, Column Grouping adds `getIsGrouped` and `getIsPlaceholder`, while Aggregation adds `getIsAggregated`.
+The `assignCellPrototype` method in a table feature is responsible for adding methods to the shared `cell` prototype. For example, Column Grouping adds `getIsGrouped` and `getIsPlaceholder`, while Aggregation adds `getIsAggregated`. The `initCellInstanceData` method is available for per-cell instance data or caches that cannot live on the shared prototype. Cells are constructed lazily on first access per row/column pair and cached, so it runs once per cell instance.
 
 ### Adding a Custom Feature
 
@@ -286,10 +319,15 @@ export const densityPlugin: TableFeature = {
   // initRowInstanceData: (row) => {},
   // if you need to add cell instance APIs...
   // assignCellPrototype: (prototype, table) => {},
+  // initCellInstanceData: (cell) => {},
   // if you need to add column instance APIs...
   // assignColumnPrototype: (prototype, table) => {},
+  // initColumnInstanceData: (column) => {},
   // if you need to add header instance APIs...
   // assignHeaderPrototype: (prototype, table) => {},
+  // initHeaderInstanceData: (header) => {},
+  // if you need to add header group instance data...
+  // initHeaderGroupInstanceData: (headerGroup) => {},
 }
 ```
 
diff --git a/docs/framework/lit/guide/custom-features.md b/docs/framework/lit/guide/custom-features.md
index a0367cb68c..230212a129 100644
--- a/docs/framework/lit/guide/custom-features.md
+++ b/docs/framework/lit/guide/custom-features.md
@@ -68,6 +68,33 @@ export interface TableFeature {
     table: Table_Internal<TFeatures, TData>,
   ) => Partial<TableOptions_All<TFeatures, TData>>
   getInitialState?: (initialState: Partial<TableState_All>) => TableState_All
+  initCellInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    cell: Cell<TFeatures, TData, TValue>,
+  ) => void
+  initColumnInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    column: Column<TFeatures, TData, TValue>,
+  ) => void
+  initHeaderGroupInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+  >(
+    headerGroup: HeaderGroup<TFeatures, TData>,
+  ) => void
+  initHeaderInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    header: Header<TFeatures, TData, TValue>,
+  ) => void
   initRowInstanceData?: <
     TFeatures extends TableFeatures,
     TData extends RowData,
@@ -125,15 +152,21 @@ The `constructTableAPIs` method in a table feature is exclusively responsible fo
 
 <br />
 
-#### assignHeaderPrototype
+#### assignHeaderPrototype and initHeaderInstanceData
+
+The `assignHeaderPrototype` method in a table feature is responsible for adding methods to the shared `header` prototype. For example, the [Column Sizing](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/column-sizing/columnSizingFeature.ts) feature adds header instance API methods such as `getStart`. So then, when you call `header.getStart()`, you are calling a method that was added by the column sizing feature. The `initHeaderInstanceData` method is available for per-header instance data or caches that cannot live on the shared prototype. It runs during header construction, before sub-headers are populated and before the header is linked to its header group. Headers are reconstructed whenever header groups recompute, so it reruns on every rebuild.
+
+<br />
+
+#### initHeaderGroupInstanceData
 
-The `assignHeaderPrototype` method in a table feature is responsible for adding methods to the shared `header` prototype. For example, the [Column Sizing](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/column-sizing/columnSizingFeature.ts) feature adds header instance API methods such as `getStart`. So then, when you call `header.getStart()`, you are calling a method that was added by the column sizing feature.
+The `initHeaderGroupInstanceData` method is available for per-header-group instance data. Header groups have no shared prototype, so this is their only per-instance extension point. It runs after a header group's `depth`, `id`, and fully populated `headers` array have been assigned, and reruns whenever header groups are rebuilt.
 
 <br />
 
-#### assignColumnPrototype
+#### assignColumnPrototype and initColumnInstanceData
 
-The `assignColumnPrototype` method in a table feature is responsible for adding methods to the shared `column` prototype. For example, the [Sorting](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-sorting/rowSortingFeature.ts) feature adds column instance API methods such as `getNextSortingOrder`, `toggleSorting`, etc. So then, when you call `column.toggleSorting()`, you are calling a method that was added by the row sorting feature.
+The `assignColumnPrototype` method in a table feature is responsible for adding methods to the shared `column` prototype. For example, the [Sorting](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-sorting/rowSortingFeature.ts) feature adds column instance API methods such as `getNextSortingOrder`, `toggleSorting`, etc. So then, when you call `column.toggleSorting()`, you are calling a method that was added by the row sorting feature. The `initColumnInstanceData` method is available for per-column instance data or caches that cannot live on the shared prototype. For example, the [Aggregation](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-aggregation/rowAggregationFeature.ts) feature uses it to set up a per-column aggregation cache.
 
 <br />
 
@@ -143,9 +176,9 @@ The `assignRowPrototype` method in a table feature is responsible for adding met
 
 <br />
 
-#### assignCellPrototype
+#### assignCellPrototype and initCellInstanceData
 
-The `assignCellPrototype` method in a table feature is responsible for adding methods to the shared `cell` prototype. For example, Column Grouping adds `getIsGrouped` and `getIsPlaceholder`, while Aggregation adds `getIsAggregated`.
+The `assignCellPrototype` method in a table feature is responsible for adding methods to the shared `cell` prototype. For example, Column Grouping adds `getIsGrouped` and `getIsPlaceholder`, while Aggregation adds `getIsAggregated`. The `initCellInstanceData` method is available for per-cell instance data or caches that cannot live on the shared prototype. Cells are constructed lazily on first access per row/column pair and cached, so it runs once per cell instance.
 
 ## Adding a Custom Feature
 
@@ -266,10 +299,15 @@ export const densityPlugin: TableFeature = {
   // initRowInstanceData: (row) => {},
   // if you need to add cell instance APIs...
   // assignCellPrototype: (prototype, table) => {},
+  // initCellInstanceData: (cell) => {},
   // if you need to add column instance APIs...
   // assignColumnPrototype: (prototype, table) => {},
+  // initColumnInstanceData: (column) => {},
   // if you need to add header instance APIs...
   // assignHeaderPrototype: (prototype, table) => {},
+  // initHeaderInstanceData: (header) => {},
+  // if you need to add header group instance data...
+  // initHeaderGroupInstanceData: (headerGroup) => {},
 }
 ```
 
diff --git a/docs/framework/preact/guide/custom-features.md b/docs/framework/preact/guide/custom-features.md
index 6219f20e7e..bce4072fb1 100644
--- a/docs/framework/preact/guide/custom-features.md
+++ b/docs/framework/preact/guide/custom-features.md
@@ -76,6 +76,33 @@ export interface TableFeature {
     table: Table_Internal<TFeatures, TData>,
   ) => Partial<TableOptions_All<TFeatures, TData>>
   getInitialState?: (initialState: Partial<TableState_All>) => TableState_All
+  initCellInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    cell: Cell<TFeatures, TData, TValue>,
+  ) => void
+  initColumnInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    column: Column<TFeatures, TData, TValue>,
+  ) => void
+  initHeaderGroupInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+  >(
+    headerGroup: HeaderGroup<TFeatures, TData>,
+  ) => void
+  initHeaderInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    header: Header<TFeatures, TData, TValue>,
+  ) => void
   initRowInstanceData?: <
     TFeatures extends TableFeatures,
     TData extends RowData,
@@ -133,15 +160,21 @@ The `constructTableAPIs` method in a table feature is exclusively responsible fo
 
 <br />
 
-##### assignHeaderPrototype
+##### assignHeaderPrototype and initHeaderInstanceData
+
+The `assignHeaderPrototype` method in a table feature is responsible for adding methods to the shared `header` prototype. For example, the [Column Sizing](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/column-sizing/columnSizingFeature.ts) feature adds header instance API methods such as `getStart`. So then, when you call `header.getStart()`, you are calling a method that was added by the column sizing feature. The `initHeaderInstanceData` method is available for per-header instance data or caches that cannot live on the shared prototype. It runs during header construction, before sub-headers are populated and before the header is linked to its header group. Headers are reconstructed whenever header groups recompute, so it reruns on every rebuild.
+
+<br />
+
+##### initHeaderGroupInstanceData
 
-The `assignHeaderPrototype` method in a table feature is responsible for adding methods to the shared `header` prototype. For example, the [Column Sizing](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/column-sizing/columnSizingFeature.ts) feature adds header instance API methods such as `getStart`. So then, when you call `header.getStart()`, you are calling a method that was added by the column sizing feature.
+The `initHeaderGroupInstanceData` method is available for per-header-group instance data. Header groups have no shared prototype, so this is their only per-instance extension point. It runs after a header group's `depth`, `id`, and fully populated `headers` array have been assigned, and reruns whenever header groups are rebuilt.
 
 <br />
 
-##### assignColumnPrototype
+##### assignColumnPrototype and initColumnInstanceData
 
-The `assignColumnPrototype` method in a table feature is responsible for adding methods to the shared `column` prototype. For example, the [Sorting](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-sorting/rowSortingFeature.ts) feature adds column instance API methods such as `getNextSortingOrder`, `toggleSorting`, etc. So then, when you call `column.toggleSorting()`, you are calling a method that was added by the row sorting feature.
+The `assignColumnPrototype` method in a table feature is responsible for adding methods to the shared `column` prototype. For example, the [Sorting](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-sorting/rowSortingFeature.ts) feature adds column instance API methods such as `getNextSortingOrder`, `toggleSorting`, etc. So then, when you call `column.toggleSorting()`, you are calling a method that was added by the row sorting feature. The `initColumnInstanceData` method is available for per-column instance data or caches that cannot live on the shared prototype. For example, the [Aggregation](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-aggregation/rowAggregationFeature.ts) feature uses it to set up a per-column aggregation cache.
 
 <br />
 
@@ -151,9 +184,9 @@ The `assignRowPrototype` method in a table feature is responsible for adding met
 
 <br />
 
-##### assignCellPrototype
+##### assignCellPrototype and initCellInstanceData
 
-The `assignCellPrototype` method in a table feature is responsible for adding methods to the shared `cell` prototype. For example, Column Grouping adds `getIsGrouped` and `getIsPlaceholder`, while Aggregation adds `getIsAggregated`.
+The `assignCellPrototype` method in a table feature is responsible for adding methods to the shared `cell` prototype. For example, Column Grouping adds `getIsGrouped` and `getIsPlaceholder`, while Aggregation adds `getIsAggregated`. The `initCellInstanceData` method is available for per-cell instance data or caches that cannot live on the shared prototype. Cells are constructed lazily on first access per row/column pair and cached, so it runs once per cell instance.
 
 ### Adding a Custom Feature
 
@@ -274,10 +307,15 @@ export const densityPlugin: TableFeature = {
   // initRowInstanceData: (row) => {},
   // if you need to add cell instance APIs...
   // assignCellPrototype: (prototype, table) => {},
+  // initCellInstanceData: (cell) => {},
   // if you need to add column instance APIs...
   // assignColumnPrototype: (prototype, table) => {},
+  // initColumnInstanceData: (column) => {},
   // if you need to add header instance APIs...
   // assignHeaderPrototype: (prototype, table) => {},
+  // initHeaderInstanceData: (header) => {},
+  // if you need to add header group instance data...
+  // initHeaderGroupInstanceData: (headerGroup) => {},
 }
 ```
 
diff --git a/docs/framework/react/guide/custom-features.md b/docs/framework/react/guide/custom-features.md
index 9884a75fa6..42aad2fb41 100644
--- a/docs/framework/react/guide/custom-features.md
+++ b/docs/framework/react/guide/custom-features.md
@@ -76,6 +76,33 @@ export interface TableFeature {
     table: Table_Internal<TFeatures, TData>,
   ) => Partial<TableOptions_All<TFeatures, TData>>
   getInitialState?: (initialState: Partial<TableState_All>) => TableState_All
+  initCellInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    cell: Cell<TFeatures, TData, TValue>,
+  ) => void
+  initColumnInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    column: Column<TFeatures, TData, TValue>,
+  ) => void
+  initHeaderGroupInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+  >(
+    headerGroup: HeaderGroup<TFeatures, TData>,
+  ) => void
+  initHeaderInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    header: Header<TFeatures, TData, TValue>,
+  ) => void
   initRowInstanceData?: <
     TFeatures extends TableFeatures,
     TData extends RowData,
@@ -133,15 +160,21 @@ The `constructTableAPIs` method in a table feature is exclusively responsible fo
 
 <br />
 
-##### assignHeaderPrototype
+##### assignHeaderPrototype and initHeaderInstanceData
+
+The `assignHeaderPrototype` method in a table feature is responsible for adding methods to the shared `header` prototype. For example, the [Column Sizing](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/column-sizing/columnSizingFeature.ts) feature adds header instance API methods such as `getStart`. So then, when you call `header.getStart()`, you are calling a method that was added by the column sizing feature. The `initHeaderInstanceData` method is available for per-header instance data or caches that cannot live on the shared prototype. It runs during header construction, before sub-headers are populated and before the header is linked to its header group. Headers are reconstructed whenever header groups recompute, so it reruns on every rebuild.
+
+<br />
+
+##### initHeaderGroupInstanceData
 
-The `assignHeaderPrototype` method in a table feature is responsible for adding methods to the shared `header` prototype. For example, the [Column Sizing](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/column-sizing/columnSizingFeature.ts) feature adds header instance API methods such as `getStart`. So then, when you call `header.getStart()`, you are calling a method that was added by the column sizing feature.
+The `initHeaderGroupInstanceData` method is available for per-header-group instance data. Header groups have no shared prototype, so this is their only per-instance extension point. It runs after a header group's `depth`, `id`, and fully populated `headers` array have been assigned, and reruns whenever header groups are rebuilt.
 
 <br />
 
-##### assignColumnPrototype
+##### assignColumnPrototype and initColumnInstanceData
 
-The `assignColumnPrototype` method in a table feature is responsible for adding methods to the shared `column` prototype. For example, the [Sorting](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-sorting/rowSortingFeature.ts) feature adds column instance API methods such as `getNextSortingOrder`, `toggleSorting`, etc. So then, when you call `column.toggleSorting()`, you are calling a method that was added by the row sorting feature.
+The `assignColumnPrototype` method in a table feature is responsible for adding methods to the shared `column` prototype. For example, the [Sorting](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-sorting/rowSortingFeature.ts) feature adds column instance API methods such as `getNextSortingOrder`, `toggleSorting`, etc. So then, when you call `column.toggleSorting()`, you are calling a method that was added by the row sorting feature. The `initColumnInstanceData` method is available for per-column instance data or caches that cannot live on the shared prototype. For example, the [Aggregation](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-aggregation/rowAggregationFeature.ts) feature uses it to set up a per-column aggregation cache.
 
 <br />
 
@@ -151,9 +184,9 @@ The `assignRowPrototype` method in a table feature is responsible for adding met
 
 <br />
 
-##### assignCellPrototype
+##### assignCellPrototype and initCellInstanceData
 
-The `assignCellPrototype` method in a table feature is responsible for adding methods to the shared `cell` prototype. For example, Column Grouping adds `getIsGrouped` and `getIsPlaceholder`, while Aggregation adds `getIsAggregated`.
+The `assignCellPrototype` method in a table feature is responsible for adding methods to the shared `cell` prototype. For example, Column Grouping adds `getIsGrouped` and `getIsPlaceholder`, while Aggregation adds `getIsAggregated`. The `initCellInstanceData` method is available for per-cell instance data or caches that cannot live on the shared prototype. Cells are constructed lazily on first access per row/column pair and cached, so it runs once per cell instance.
 
 ### Adding a Custom Feature
 
@@ -274,10 +307,15 @@ export const densityPlugin: TableFeature = {
   // initRowInstanceData: (row) => {},
   // if you need to add cell instance APIs...
   // assignCellPrototype: (prototype, table) => {},
+  // initCellInstanceData: (cell) => {},
   // if you need to add column instance APIs...
   // assignColumnPrototype: (prototype, table) => {},
+  // initColumnInstanceData: (column) => {},
   // if you need to add header instance APIs...
   // assignHeaderPrototype: (prototype, table) => {},
+  // initHeaderInstanceData: (header) => {},
+  // if you need to add header group instance data...
+  // initHeaderGroupInstanceData: (headerGroup) => {},
 }
 ```
 
diff --git a/docs/framework/solid/guide/custom-features.md b/docs/framework/solid/guide/custom-features.md
index 4e8e4093fe..6faf75b019 100644
--- a/docs/framework/solid/guide/custom-features.md
+++ b/docs/framework/solid/guide/custom-features.md
@@ -70,6 +70,33 @@ export interface TableFeature {
     table: Table_Internal<TFeatures, TData>,
   ) => Partial<TableOptions_All<TFeatures, TData>>
   getInitialState?: (initialState: Partial<TableState_All>) => TableState_All
+  initCellInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    cell: Cell<TFeatures, TData, TValue>,
+  ) => void
+  initColumnInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    column: Column<TFeatures, TData, TValue>,
+  ) => void
+  initHeaderGroupInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+  >(
+    headerGroup: HeaderGroup<TFeatures, TData>,
+  ) => void
+  initHeaderInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    header: Header<TFeatures, TData, TValue>,
+  ) => void
   initRowInstanceData?: <
     TFeatures extends TableFeatures,
     TData extends RowData,
@@ -127,15 +154,21 @@ The `constructTableAPIs` method in a table feature is exclusively responsible fo
 
 <br />
 
-#### assignHeaderPrototype
+#### assignHeaderPrototype and initHeaderInstanceData
+
+The `assignHeaderPrototype` method in a table feature is responsible for adding methods to the shared `header` prototype. For example, the [Column Sizing](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/column-sizing/columnSizingFeature.ts) feature adds header instance API methods such as `getStart`. So then, when you call `header.getStart()`, you are calling a method that was added by the column sizing feature. The `initHeaderInstanceData` method is available for per-header instance data or caches that cannot live on the shared prototype. It runs during header construction, before sub-headers are populated and before the header is linked to its header group. Headers are reconstructed whenever header groups recompute, so it reruns on every rebuild.
+
+<br />
+
+#### initHeaderGroupInstanceData
 
-The `assignHeaderPrototype` method in a table feature is responsible for adding methods to the shared `header` prototype. For example, the [Column Sizing](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/column-sizing/columnSizingFeature.ts) feature adds header instance API methods such as `getStart`. So then, when you call `header.getStart()`, you are calling a method that was added by the column sizing feature.
+The `initHeaderGroupInstanceData` method is available for per-header-group instance data. Header groups have no shared prototype, so this is their only per-instance extension point. It runs after a header group's `depth`, `id`, and fully populated `headers` array have been assigned, and reruns whenever header groups are rebuilt.
 
 <br />
 
-#### assignColumnPrototype
+#### assignColumnPrototype and initColumnInstanceData
 
-The `assignColumnPrototype` method in a table feature is responsible for adding methods to the shared `column` prototype. For example, the [Sorting](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-sorting/rowSortingFeature.ts) feature adds column instance API methods such as `getNextSortingOrder`, `toggleSorting`, etc. So then, when you call `column.toggleSorting()`, you are calling a method that was added by the row sorting feature.
+The `assignColumnPrototype` method in a table feature is responsible for adding methods to the shared `column` prototype. For example, the [Sorting](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-sorting/rowSortingFeature.ts) feature adds column instance API methods such as `getNextSortingOrder`, `toggleSorting`, etc. So then, when you call `column.toggleSorting()`, you are calling a method that was added by the row sorting feature. The `initColumnInstanceData` method is available for per-column instance data or caches that cannot live on the shared prototype. For example, the [Aggregation](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-aggregation/rowAggregationFeature.ts) feature uses it to set up a per-column aggregation cache.
 
 <br />
 
@@ -145,9 +178,9 @@ The `assignRowPrototype` method in a table feature is responsible for adding met
 
 <br />
 
-#### assignCellPrototype
+#### assignCellPrototype and initCellInstanceData
 
-The `assignCellPrototype` method in a table feature is responsible for adding methods to the shared `cell` prototype. For example, Column Grouping adds `getIsGrouped` and `getIsPlaceholder`, while Aggregation adds `getIsAggregated`.
+The `assignCellPrototype` method in a table feature is responsible for adding methods to the shared `cell` prototype. For example, Column Grouping adds `getIsGrouped` and `getIsPlaceholder`, while Aggregation adds `getIsAggregated`. The `initCellInstanceData` method is available for per-cell instance data or caches that cannot live on the shared prototype. Cells are constructed lazily on first access per row/column pair and cached, so it runs once per cell instance.
 
 ## Adding a Custom Feature
 
@@ -268,10 +301,15 @@ export const densityPlugin: TableFeature = {
   // initRowInstanceData: (row) => {},
   // if you need to add cell instance APIs...
   // assignCellPrototype: (prototype, table) => {},
+  // initCellInstanceData: (cell) => {},
   // if you need to add column instance APIs...
   // assignColumnPrototype: (prototype, table) => {},
+  // initColumnInstanceData: (column) => {},
   // if you need to add header instance APIs...
   // assignHeaderPrototype: (prototype, table) => {},
+  // initHeaderInstanceData: (header) => {},
+  // if you need to add header group instance data...
+  // initHeaderGroupInstanceData: (headerGroup) => {},
 }
 ```
 
diff --git a/docs/framework/svelte/guide/custom-features.md b/docs/framework/svelte/guide/custom-features.md
index 48bee39a91..81edc25879 100644
--- a/docs/framework/svelte/guide/custom-features.md
+++ b/docs/framework/svelte/guide/custom-features.md
@@ -70,6 +70,33 @@ export interface TableFeature {
     table: Table_Internal<TFeatures, TData>,
   ) => Partial<TableOptions_All<TFeatures, TData>>
   getInitialState?: (initialState: Partial<TableState_All>) => TableState_All
+  initCellInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    cell: Cell<TFeatures, TData, TValue>,
+  ) => void
+  initColumnInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    column: Column<TFeatures, TData, TValue>,
+  ) => void
+  initHeaderGroupInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+  >(
+    headerGroup: HeaderGroup<TFeatures, TData>,
+  ) => void
+  initHeaderInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    header: Header<TFeatures, TData, TValue>,
+  ) => void
   initRowInstanceData?: <
     TFeatures extends TableFeatures,
     TData extends RowData,
@@ -127,15 +154,21 @@ The `constructTableAPIs` method in a table feature is exclusively responsible fo
 
 <br />
 
-#### assignHeaderPrototype
+#### assignHeaderPrototype and initHeaderInstanceData
+
+The `assignHeaderPrototype` method in a table feature is responsible for adding methods to the shared `header` prototype. For example, the [Column Sizing](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/column-sizing/columnSizingFeature.ts) feature adds header instance API methods such as `getStart`. So then, when you call `header.getStart()`, you are calling a method that was added by the column sizing feature. The `initHeaderInstanceData` method is available for per-header instance data or caches that cannot live on the shared prototype. It runs during header construction, before sub-headers are populated and before the header is linked to its header group. Headers are reconstructed whenever header groups recompute, so it reruns on every rebuild.
+
+<br />
+
+#### initHeaderGroupInstanceData
 
-The `assignHeaderPrototype` method in a table feature is responsible for adding methods to the shared `header` prototype. For example, the [Column Sizing](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/column-sizing/columnSizingFeature.ts) feature adds header instance API methods such as `getStart`. So then, when you call `header.getStart()`, you are calling a method that was added by the column sizing feature.
+The `initHeaderGroupInstanceData` method is available for per-header-group instance data. Header groups have no shared prototype, so this is their only per-instance extension point. It runs after a header group's `depth`, `id`, and fully populated `headers` array have been assigned, and reruns whenever header groups are rebuilt.
 
 <br />
 
-#### assignColumnPrototype
+#### assignColumnPrototype and initColumnInstanceData
 
-The `assignColumnPrototype` method in a table feature is responsible for adding methods to the shared `column` prototype. For example, the [Sorting](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-sorting/rowSortingFeature.ts) feature adds column instance API methods such as `getNextSortingOrder`, `toggleSorting`, etc. So then, when you call `column.toggleSorting()`, you are calling a method that was added by the row sorting feature.
+The `assignColumnPrototype` method in a table feature is responsible for adding methods to the shared `column` prototype. For example, the [Sorting](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-sorting/rowSortingFeature.ts) feature adds column instance API methods such as `getNextSortingOrder`, `toggleSorting`, etc. So then, when you call `column.toggleSorting()`, you are calling a method that was added by the row sorting feature. The `initColumnInstanceData` method is available for per-column instance data or caches that cannot live on the shared prototype. For example, the [Aggregation](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-aggregation/rowAggregationFeature.ts) feature uses it to set up a per-column aggregation cache.
 
 <br />
 
@@ -145,9 +178,9 @@ The `assignRowPrototype` method in a table feature is responsible for adding met
 
 <br />
 
-#### assignCellPrototype
+#### assignCellPrototype and initCellInstanceData
 
-The `assignCellPrototype` method in a table feature is responsible for adding methods to the shared `cell` prototype. For example, Column Grouping adds `getIsGrouped` and `getIsPlaceholder`, while Aggregation adds `getIsAggregated`.
+The `assignCellPrototype` method in a table feature is responsible for adding methods to the shared `cell` prototype. For example, Column Grouping adds `getIsGrouped` and `getIsPlaceholder`, while Aggregation adds `getIsAggregated`. The `initCellInstanceData` method is available for per-cell instance data or caches that cannot live on the shared prototype. Cells are constructed lazily on first access per row/column pair and cached, so it runs once per cell instance.
 
 ## Adding a Custom Feature
 
@@ -268,10 +301,15 @@ export const densityPlugin: TableFeature = {
   // initRowInstanceData: (row) => {},
   // if you need to add cell instance APIs...
   // assignCellPrototype: (prototype, table) => {},
+  // initCellInstanceData: (cell) => {},
   // if you need to add column instance APIs...
   // assignColumnPrototype: (prototype, table) => {},
+  // initColumnInstanceData: (column) => {},
   // if you need to add header instance APIs...
   // assignHeaderPrototype: (prototype, table) => {},
+  // initHeaderInstanceData: (header) => {},
+  // if you need to add header group instance data...
+  // initHeaderGroupInstanceData: (headerGroup) => {},
 }
 ```
 
diff --git a/docs/framework/vue/guide/custom-features.md b/docs/framework/vue/guide/custom-features.md
index c908c5d87d..862de8122d 100644
--- a/docs/framework/vue/guide/custom-features.md
+++ b/docs/framework/vue/guide/custom-features.md
@@ -70,6 +70,33 @@ export interface TableFeature {
     table: Table_Internal<TFeatures, TData>,
   ) => Partial<TableOptions_All<TFeatures, TData>>
   getInitialState?: (initialState: Partial<TableState_All>) => TableState_All
+  initCellInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    cell: Cell<TFeatures, TData, TValue>,
+  ) => void
+  initColumnInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    column: Column<TFeatures, TData, TValue>,
+  ) => void
+  initHeaderGroupInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+  >(
+    headerGroup: HeaderGroup<TFeatures, TData>,
+  ) => void
+  initHeaderInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    header: Header<TFeatures, TData, TValue>,
+  ) => void
   initRowInstanceData?: <
     TFeatures extends TableFeatures,
     TData extends RowData,
@@ -127,15 +154,21 @@ The `constructTableAPIs` method in a table feature is exclusively responsible fo
 
 <br />
 
-#### assignHeaderPrototype
+#### assignHeaderPrototype and initHeaderInstanceData
+
+The `assignHeaderPrototype` method in a table feature is responsible for adding methods to the shared `header` prototype. For example, the [Column Sizing](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/column-sizing/columnSizingFeature.ts) feature adds header instance API methods such as `getStart`. So then, when you call `header.getStart()`, you are calling a method that was added by the column sizing feature. The `initHeaderInstanceData` method is available for per-header instance data or caches that cannot live on the shared prototype. It runs during header construction, before sub-headers are populated and before the header is linked to its header group. Headers are reconstructed whenever header groups recompute, so it reruns on every rebuild.
+
+<br />
+
+#### initHeaderGroupInstanceData
 
-The `assignHeaderPrototype` method in a table feature is responsible for adding methods to the shared `header` prototype. For example, the [Column Sizing](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/column-sizing/columnSizingFeature.ts) feature adds header instance API methods such as `getStart`. So then, when you call `header.getStart()`, you are calling a method that was added by the column sizing feature.
+The `initHeaderGroupInstanceData` method is available for per-header-group instance data. Header groups have no shared prototype, so this is their only per-instance extension point. It runs after a header group's `depth`, `id`, and fully populated `headers` array have been assigned, and reruns whenever header groups are rebuilt.
 
 <br />
 
-#### assignColumnPrototype
+#### assignColumnPrototype and initColumnInstanceData
 
-The `assignColumnPrototype` method in a table feature is responsible for adding methods to the shared `column` prototype. For example, the [Sorting](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-sorting/rowSortingFeature.ts) feature adds column instance API methods such as `getNextSortingOrder`, `toggleSorting`, etc. So then, when you call `column.toggleSorting()`, you are calling a method that was added by the row sorting feature.
+The `assignColumnPrototype` method in a table feature is responsible for adding methods to the shared `column` prototype. For example, the [Sorting](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-sorting/rowSortingFeature.ts) feature adds column instance API methods such as `getNextSortingOrder`, `toggleSorting`, etc. So then, when you call `column.toggleSorting()`, you are calling a method that was added by the row sorting feature. The `initColumnInstanceData` method is available for per-column instance data or caches that cannot live on the shared prototype. For example, the [Aggregation](https://github.com/TanStack/table/blob/beta/packages/table-core/src/features/row-aggregation/rowAggregationFeature.ts) feature uses it to set up a per-column aggregation cache.
 
 <br />
 
@@ -145,9 +178,9 @@ The `assignRowPrototype` method in a table feature is responsible for adding met
 
 <br />
 
-#### assignCellPrototype
+#### assignCellPrototype and initCellInstanceData
 
-The `assignCellPrototype` method in a table feature is responsible for adding methods to the shared `cell` prototype. For example, Column Grouping adds `getIsGrouped` and `getIsPlaceholder`, while Aggregation adds `getIsAggregated`.
+The `assignCellPrototype` method in a table feature is responsible for adding methods to the shared `cell` prototype. For example, Column Grouping adds `getIsGrouped` and `getIsPlaceholder`, while Aggregation adds `getIsAggregated`. The `initCellInstanceData` method is available for per-cell instance data or caches that cannot live on the shared prototype. Cells are constructed lazily on first access per row/column pair and cached, so it runs once per cell instance.
 
 ## Adding a Custom Feature
 
@@ -268,10 +301,15 @@ export const densityPlugin: TableFeature = {
   // initRowInstanceData: (row) => {},
   // if you need to add cell instance APIs...
   // assignCellPrototype: (prototype, table) => {},
+  // initCellInstanceData: (cell) => {},
   // if you need to add column instance APIs...
   // assignColumnPrototype: (prototype, table) => {},
+  // initColumnInstanceData: (column) => {},
   // if you need to add header instance APIs...
   // assignHeaderPrototype: (prototype, table) => {},
+  // initHeaderInstanceData: (header) => {},
+  // if you need to add header group instance data...
+  // initHeaderGroupInstanceData: (headerGroup) => {},
 }
 ```
 
diff --git a/docs/reference/index/functions/constructColumn.md b/docs/reference/index/functions/constructColumn.md
index 924d5bb7a0..8d5dccb313 100644
--- a/docs/reference/index/functions/constructColumn.md
+++ b/docs/reference/index/functions/constructColumn.md
@@ -13,7 +13,7 @@ function constructColumn<TFeatures, TData, TValue>(
 parent?): Column<TFeatures, TData, TValue>;
 ```
 
-Defined in: [core/columns/constructColumn.ts:36](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/columns/constructColumn.ts#L36)
+Defined in: [core/columns/constructColumn.ts:35](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/columns/constructColumn.ts#L35)
 
 Constructs a column instance from normalized table internals.
 
diff --git a/docs/reference/index/functions/makeStateUpdater.md b/docs/reference/index/functions/makeStateUpdater.md
index f7f327f865..436b09ba16 100644
--- a/docs/reference/index/functions/makeStateUpdater.md
+++ b/docs/reference/index/functions/makeStateUpdater.md
@@ -57,7 +57,7 @@ The updater writes through the table base atom for the slice and supports both v
 
 #### updater
 
-[`Updater`](../type-aliases/Updater.md)\<`TableState_WorkerRowModels` & [`TableState_ColumnGrouping`](../interfaces/TableState_ColumnGrouping.md) & [`TableState_ColumnPinning`](../interfaces/TableState_ColumnPinning.md) & [`TableState_ColumnSizing`](../interfaces/TableState_ColumnSizing.md) & [`TableState_ColumnResizing`](../interfaces/TableState_ColumnResizing.md) & [`TableState_GlobalFiltering`](../interfaces/TableState_GlobalFiltering.md) & [`TableState_ColumnVisibility`](../interfaces/TableState_ColumnVisibility.md) & [`TableState_RowExpanding`](../interfaces/TableState_RowExpanding.md) & [`TableState_RowPinning`](../interfaces/TableState_RowPinning.md) & [`TableState_RowSelection`](../interfaces/TableState_RowSelection.md) & [`TableState_ColumnFiltering`](../interfaces/TableState_ColumnFiltering.md) & [`TableState_RowPagination`](../interfaces/TableState_RowPagination.md) & [`TableState_RowSorting`](../interfaces/TableState_RowSorting.md) & [`TableState_ColumnOrdering`](../interfaces/TableState_ColumnOrdering.md)\[`K` & 
+[`Updater`](../type-aliases/Updater.md)\<`TableState_WorkerRowModels` & [`TableState_RowSorting`](../interfaces/TableState_RowSorting.md) & [`TableState_ColumnPinning`](../interfaces/TableState_ColumnPinning.md) & [`TableState_ColumnSizing`](../interfaces/TableState_ColumnSizing.md) & [`TableState_ColumnResizing`](../interfaces/TableState_ColumnResizing.md) & [`TableState_GlobalFiltering`](../interfaces/TableState_GlobalFiltering.md) & [`TableState_ColumnOrdering`](../interfaces/TableState_ColumnOrdering.md) & [`TableState_ColumnVisibility`](../interfaces/TableState_ColumnVisibility.md) & [`TableState_RowExpanding`](../interfaces/TableState_RowExpanding.md) & [`TableState_RowPinning`](../interfaces/TableState_RowPinning.md) & [`TableState_RowSelection`](../interfaces/TableState_RowSelection.md) & [`TableState_ColumnFiltering`](../interfaces/TableState_ColumnFiltering.md) & [`TableState_RowPagination`](../interfaces/TableState_RowPagination.md) & [`TableState_ColumnGrouping`](../interfaces/TableState_ColumnGrouping.md)\[`K` & 
   \| `"expanded"`
   \| `"columnFilters"`
   \| `"globalFilter"`
diff --git a/docs/reference/index/interfaces/ColumnDef_RowSorting.md b/docs/reference/index/interfaces/ColumnDef_RowSorting.md
index b3161929cd..3b1ad97805 100644
--- a/docs/reference/index/interfaces/ColumnDef_RowSorting.md
+++ b/docs/reference/index/interfaces/ColumnDef_RowSorting.md
@@ -84,7 +84,7 @@ The sorting function to use with this column.
 ### sortUndefined?
 
 ```ts
-optional sortUndefined: false | 1 | "first" | "last" | -1;
+optional sortUndefined: false | 1 | -1 | "first" | "last";
 ```
 
 Defined in: [features/row-sorting/rowSortingFeature.types.ts:153](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-sorting/rowSortingFeature.types.ts#L153)
diff --git a/docs/reference/index/interfaces/FeatureSlotPrereqs.md b/docs/reference/index/interfaces/FeatureSlotPrereqs.md
index 3c596f6235..d78f968f7d 100644
--- a/docs/reference/index/interfaces/FeatureSlotPrereqs.md
+++ b/docs/reference/index/interfaces/FeatureSlotPrereqs.md
@@ -5,7 +5,7 @@ title: FeatureSlotPrereqs
 
 # Interface: FeatureSlotPrereqs
 
-Defined in: [types/TableFeatures.ts:91](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L91)
+Defined in: [types/TableFeatures.ts:94](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L94)
 
 Maps each row model and fn registry slot to the feature(s) that must be
 registered alongside it in the same features object.
@@ -21,7 +21,7 @@ interface to get the same validation from `tableFeatures()`.
 aggregationFns: "rowAggregationFeature";
 ```
 
-Defined in: [types/TableFeatures.ts:95](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L95)
+Defined in: [types/TableFeatures.ts:98](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L98)
 
 Named aggregation functions require the independent aggregation feature.
 
@@ -33,7 +33,7 @@ Named aggregation functions require the independent aggregation feature.
 columnResizingFeature: "columnSizingFeature";
 ```
 
-Defined in: [types/TableFeatures.ts:99](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L99)
+Defined in: [types/TableFeatures.ts:102](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L102)
 
 Column resizing builds on the column sizing state and APIs.
 
@@ -45,7 +45,7 @@ Column resizing builds on the column sizing state and APIs.
 expandedRowModel: "rowExpandingFeature";
 ```
 
-Defined in: [types/TableFeatures.ts:103](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L103)
+Defined in: [types/TableFeatures.ts:106](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L106)
 
 Expanded row-model factories require row expanding APIs and state.
 
@@ -57,7 +57,7 @@ Expanded row-model factories require row expanding APIs and state.
 facetedMinMaxValues: "columnFacetingFeature";
 ```
 
-Defined in: [types/TableFeatures.ts:107](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L107)
+Defined in: [types/TableFeatures.ts:110](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L110)
 
 Faceted min/max factories require column faceting APIs.
 
@@ -69,7 +69,7 @@ Faceted min/max factories require column faceting APIs.
 facetedRowModel: "columnFacetingFeature";
 ```
 
-Defined in: [types/TableFeatures.ts:111](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L111)
+Defined in: [types/TableFeatures.ts:114](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L114)
 
 Faceted row-model factories require column faceting APIs.
 
@@ -81,7 +81,7 @@ Faceted row-model factories require column faceting APIs.
 facetedUniqueValues: "columnFacetingFeature";
 ```
 
-Defined in: [types/TableFeatures.ts:115](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L115)
+Defined in: [types/TableFeatures.ts:118](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L118)
 
 Faceted unique-value factories require column faceting APIs.
 
@@ -93,7 +93,7 @@ Faceted unique-value factories require column faceting APIs.
 filteredRowModel: "columnFilteringFeature";
 ```
 
-Defined in: [types/TableFeatures.ts:119](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L119)
+Defined in: [types/TableFeatures.ts:122](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L122)
 
 Filtered row-model factories require column filtering APIs and state.
 
@@ -105,7 +105,7 @@ Filtered row-model factories require column filtering APIs and state.
 filterFns: "columnFilteringFeature";
 ```
 
-Defined in: [types/TableFeatures.ts:123](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L123)
+Defined in: [types/TableFeatures.ts:126](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L126)
 
 Named filter functions are only meaningful when column filtering is enabled.
 
@@ -117,7 +117,7 @@ Named filter functions are only meaningful when column filtering is enabled.
 filterMeta: "columnFilteringFeature";
 ```
 
-Defined in: [types/TableFeatures.ts:127](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L127)
+Defined in: [types/TableFeatures.ts:130](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L130)
 
 Filter metadata types are only read and written by filtering features.
 
@@ -129,7 +129,7 @@ Filter metadata types are only read and written by filtering features.
 globalFilteringFeature: "columnFilteringFeature";
 ```
 
-Defined in: [types/TableFeatures.ts:131](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L131)
+Defined in: [types/TableFeatures.ts:134](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L134)
 
 Global filtering builds on column filtering state and filter functions.
 
@@ -141,7 +141,7 @@ Global filtering builds on column filtering state and filter functions.
 groupedRowModel: "columnGroupingFeature";
 ```
 
-Defined in: [types/TableFeatures.ts:135](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L135)
+Defined in: [types/TableFeatures.ts:138](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L138)
 
 Grouped row-model factories require column grouping APIs and state.
 
@@ -153,7 +153,7 @@ Grouped row-model factories require column grouping APIs and state.
 paginatedRowModel: "rowPaginationFeature";
 ```
 
-Defined in: [types/TableFeatures.ts:139](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L139)
+Defined in: [types/TableFeatures.ts:142](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L142)
 
 Paginated row-model factories require row pagination APIs and state.
 
@@ -165,7 +165,7 @@ Paginated row-model factories require row pagination APIs and state.
 sortedRowModel: "rowSortingFeature";
 ```
 
-Defined in: [types/TableFeatures.ts:143](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L143)
+Defined in: [types/TableFeatures.ts:146](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L146)
 
 Sorted row-model factories require row sorting APIs and state.
 
@@ -177,6 +177,6 @@ Sorted row-model factories require row sorting APIs and state.
 sortFns: "rowSortingFeature";
 ```
 
-Defined in: [types/TableFeatures.ts:147](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L147)
+Defined in: [types/TableFeatures.ts:150](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L150)
 
 Named sorting functions are only meaningful when row sorting is enabled.
diff --git a/docs/reference/index/interfaces/Plugins.md b/docs/reference/index/interfaces/Plugins.md
index 2d570a56eb..e5f42aeba0 100644
--- a/docs/reference/index/interfaces/Plugins.md
+++ b/docs/reference/index/interfaces/Plugins.md
@@ -5,7 +5,7 @@ title: Plugins
 
 # Interface: Plugins
 
-Defined in: [types/TableFeatures.ts:57](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L57)
+Defined in: [types/TableFeatures.ts:60](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L60)
 
 Declaration-merge target for custom table features.
 
diff --git a/docs/reference/index/interfaces/Row_Aggregation.md b/docs/reference/index/interfaces/Row_Aggregation.md
index cac19b6a48..7e0eab76e9 100644
--- a/docs/reference/index/interfaces/Row_Aggregation.md
+++ b/docs/reference/index/interfaces/Row_Aggregation.md
@@ -11,12 +11,12 @@ Internal per-row cache used while grouped aggregates are evaluated.
 
 ## Properties
 
-### \_aggregationValuesCache
+### \_aggregationValuesCache?
 
 ```ts
-_aggregationValuesCache: Record<string, unknown>;
+optional _aggregationValuesCache: Record<string, unknown>;
 ```
 
 Defined in: [features/row-aggregation/rowAggregationFeature.types.ts:306](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/rowAggregationFeature.types.ts#L306)
 
-Cached aggregate results keyed by column id.
+Cached aggregate results keyed by column id; created lazily on grouped rows.
diff --git a/docs/reference/index/interfaces/TableFeature.md b/docs/reference/index/interfaces/TableFeature.md
index 637022ab06..b848353d04 100644
--- a/docs/reference/index/interfaces/TableFeature.md
+++ b/docs/reference/index/interfaces/TableFeature.md
@@ -5,14 +5,14 @@ title: TableFeature
 
 # Interface: TableFeature
 
-Defined in: [types/TableFeatures.ts:316](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L316)
+Defined in: [types/TableFeatures.ts:319](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L319)
 
 Lifecycle hooks and defaults contributed by a table feature.
 
 Feature objects are registered in the table's `features` option. They can
 contribute default state/options, default column definitions, table APIs,
-shared prototype APIs for rows/columns/headers/cells, and per-instance row
-or column data.
+shared prototype APIs for rows/columns/headers/cells, and per-instance data
+for tables, columns, rows, headers, header groups, and cells.
 
 ## Properties
 
@@ -22,7 +22,7 @@ or column data.
 optional assignCellPrototype: <TFeatures, TData>(prototype, table) => void;
 ```
 
-Defined in: [types/TableFeatures.ts:325](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L325)
+Defined in: [types/TableFeatures.ts:328](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L328)
 
 Adds feature methods to the shared cell prototype for a table.
 
@@ -63,7 +63,7 @@ per-cell mutable data.
 optional assignColumnPrototype: <TFeatures, TData>(prototype, table) => void;
 ```
 
-Defined in: [types/TableFeatures.ts:340](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L340)
+Defined in: [types/TableFeatures.ts:343](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L343)
 
 Adds feature methods to the shared column prototype for a table.
 
@@ -104,7 +104,7 @@ than per-column mutable data.
 optional assignHeaderPrototype: <TFeatures, TData>(prototype, table) => void;
 ```
 
-Defined in: [types/TableFeatures.ts:355](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L355)
+Defined in: [types/TableFeatures.ts:358](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L358)
 
 Adds feature methods to the shared header prototype for a table.
 
@@ -145,7 +145,7 @@ than per-header mutable data.
 optional assignRowPrototype: <TFeatures, TData>(prototype, table) => void;
 ```
 
-Defined in: [types/TableFeatures.ts:370](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L370)
+Defined in: [types/TableFeatures.ts:373](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L373)
 
 Adds feature methods to the shared row prototype for a table.
 
@@ -186,7 +186,7 @@ mutable data.
 optional constructTableAPIs: <TFeatures, TData>(table) => void;
 ```
 
-Defined in: [types/TableFeatures.ts:383](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L383)
+Defined in: [types/TableFeatures.ts:386](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L386)
 
 Adds feature APIs directly to the table instance.
 
@@ -224,7 +224,7 @@ feature's `initTableInstanceData` hook has completed.
 optional getDefaultColumnDef: <TFeatures, TData, TValue>() => ColumnDefBase_All<TFeatures, TData, TValue>;
 ```
 
-Defined in: [types/TableFeatures.ts:393](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L393)
+Defined in: [types/TableFeatures.ts:396](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L396)
 
 Returns default column definition options contributed by this feature.
 
@@ -258,7 +258,7 @@ resolved, so users can override values supplied here.
 optional getDefaultTableOptions: <TFeatures, TData>(table) => Partial<TableOptions_All<TFeatures, TData>>;
 ```
 
-Defined in: [types/TableFeatures.ts:406](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L406)
+Defined in: [types/TableFeatures.ts:409](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L409)
 
 Returns default table options contributed by this feature.
 
@@ -295,7 +295,7 @@ here.
 optional getInitialState: (initialState) => TableState_All;
 ```
 
-Defined in: [types/TableFeatures.ts:420](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L420)
+Defined in: [types/TableFeatures.ts:423](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L423)
 
 Returns this feature's initial table state.
 
@@ -316,13 +316,55 @@ override feature defaults.
 
 ***
 
+### initCellInstanceData()?
+
+```ts
+optional initCellInstanceData: <TFeatures, TData, TValue>(cell) => void;
+```
+
+Defined in: [types/TableFeatures.ts:449](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L449)
+
+Initializes instance-specific data on each cell.
+
+This runs for every constructed cell after core cell fields such as `id`,
+`column`, and `row` have been assigned. Cells are constructed lazily on
+first access per row/column pair and cached, so this runs once per cell
+instance. Use this for per-cell mutable data, caches, or annotations.
+Shared methods should be assigned via `assignCellPrototype` instead.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+##### TValue
+
+`TValue` *extends* `unknown` = `unknown`
+
+#### Parameters
+
+##### cell
+
+[`Cell`](../type-aliases/Cell.md)\<`TFeatures`, `TData`, `TValue`\>
+
+#### Returns
+
+`void`
+
+***
+
 ### initColumnInstanceData()?
 
 ```ts
 optional initColumnInstanceData: <TFeatures, TData, TValue>(column) => void;
 ```
 
-Defined in: [types/TableFeatures.ts:445](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L445)
+Defined in: [types/TableFeatures.ts:464](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L464)
 
 Initializes instance-specific data on each column.
 
@@ -357,13 +399,95 @@ methods should be assigned via `assignColumnPrototype` instead.
 
 ***
 
+### initHeaderGroupInstanceData()?
+
+```ts
+optional initHeaderGroupInstanceData: <TFeatures, TData>(headerGroup) => void;
+```
+
+Defined in: [types/TableFeatures.ts:480](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L480)
+
+Initializes instance-specific data on each header group.
+
+This runs for every constructed header group after `depth`, `id`, and the
+fully populated `headers` array have been assigned. Header groups have no
+shared prototype, so this is their only per-instance extension point.
+Header groups are reconstructed whenever they recompute (e.g. column
+visibility, order, or pinning changes), so this reruns on every rebuild.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+#### Parameters
+
+##### headerGroup
+
+[`HeaderGroup`](HeaderGroup.md)\<`TFeatures`, `TData`\>
+
+#### Returns
+
+`void`
+
+***
+
+### initHeaderInstanceData()?
+
+```ts
+optional initHeaderInstanceData: <TFeatures, TData, TValue>(header) => void;
+```
+
+Defined in: [types/TableFeatures.ts:497](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L497)
+
+Initializes instance-specific data on each header.
+
+This runs for every constructed header after core header fields such as
+`id`, `column`, `depth`, `index`, and `isPlaceholder` have been assigned,
+but before `subHeaders` are populated and before `headerGroup` is linked.
+Headers are reconstructed on every header group rebuild, so this reruns
+on every rebuild. Use this for per-header mutable data, caches, or
+annotations. Shared methods should be assigned via `assignHeaderPrototype`
+instead.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+##### TValue
+
+`TValue` *extends* `unknown` = `unknown`
+
+#### Parameters
+
+##### header
+
+[`Header`](../type-aliases/Header.md)\<`TFeatures`, `TData`, `TValue`\>
+
+#### Returns
+
+`void`
+
+***
+
 ### initRowInstanceData()?
 
 ```ts
 optional initRowInstanceData: <TFeatures, TData>(row) => void;
 ```
 
-Defined in: [types/TableFeatures.ts:460](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L460)
+Defined in: [types/TableFeatures.ts:512](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L512)
 
 Initializes instance-specific data on each row.
 
@@ -400,7 +524,7 @@ should be assigned via `assignRowPrototype` instead.
 optional initTableInstanceData: <TFeatures, TData>(table) => void;
 ```
 
-Defined in: [types/TableFeatures.ts:431](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L431)
+Defined in: [types/TableFeatures.ts:434](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L434)
 
 Initializes mutable, non-reactive data owned by this feature on the table
 instance.
@@ -439,7 +563,7 @@ methods. Table resets do not rerun this hook; use
 optional resetTableInstanceData: <TFeatures, TData>(table) => void;
 ```
 
-Defined in: [types/TableFeatures.ts:473](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L473)
+Defined in: [types/TableFeatures.ts:525](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L525)
 
 Resets mutable, non-reactive table-instance data owned by this feature.
 
diff --git a/docs/reference/index/interfaces/TableFeatures.md b/docs/reference/index/interfaces/TableFeatures.md
index 8f41baca2c..b29bf14067 100644
--- a/docs/reference/index/interfaces/TableFeatures.md
+++ b/docs/reference/index/interfaces/TableFeatures.md
@@ -5,7 +5,7 @@ title: TableFeatures
 
 # Interface: TableFeatures
 
-Defined in: [types/TableFeatures.ts:181](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L181)
+Defined in: [types/TableFeatures.ts:184](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L184)
 
 Complete feature registry for a table.
 
@@ -27,7 +27,7 @@ options, and state types.
 optional aggregationFns: Record<string, AggregationFnDef<any, any, any, any>>;
 ```
 
-Defined in: [types/TableFeatures.ts:193](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L193)
+Defined in: [types/TableFeatures.ts:196](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L196)
 
 Registry of aggregation functions available to this table by name.
 
@@ -88,7 +88,7 @@ Defined in: [features/stockFeatures.ts:21](https://github.com/TanStack/table/blo
 optional columnMeta: object;
 ```
 
-Defined in: [types/TableFeatures.ts:204](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L204)
+Defined in: [types/TableFeatures.ts:207](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L207)
 
 Type-only slot for declaring the type of `columnDef.meta` for all columns
 of this table.
@@ -233,7 +233,7 @@ Defined in: [core/coreFeatures.ts:10](https://github.com/TanStack/table/blob/mai
 optional coreRowModel: (table) => () => RowModel<any, any>;
 ```
 
-Defined in: [types/TableFeatures.ts:209](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L209)
+Defined in: [types/TableFeatures.ts:212](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L212)
 
 Factory for the table's core (unmodified) row model. Defaults to the
 built-in `createCoreRowModel()` when omitted.
@@ -304,7 +304,7 @@ Defined in: [core/coreFeatures.ts:16](https://github.com/TanStack/table/blob/mai
 optional expandedRowModel: (table) => () => RowModel<any, any>;
 ```
 
-Defined in: [types/TableFeatures.ts:215](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L215)
+Defined in: [types/TableFeatures.ts:218](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L218)
 
 Factory for the client-side expanded row model. Pass the exported
 `createExpandedRowModel()` or implement your own. Not needed for
@@ -334,7 +334,7 @@ server-side expansion.
 optional facetedMinMaxValues: (table, columnId) => () => [number, number] | undefined;
 ```
 
-Defined in: [types/TableFeatures.ts:221](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L221)
+Defined in: [types/TableFeatures.ts:224](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L224)
 
 Factory for per-column faceted min/max values. Pass the exported
 `createFacetedMinMaxValues()` or implement your own. Not needed for
@@ -368,7 +368,7 @@ server-side faceting.
 optional facetedRowModel: (table, columnId) => () => RowModel<any, any>;
 ```
 
-Defined in: [types/TableFeatures.ts:230](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L230)
+Defined in: [types/TableFeatures.ts:233](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L233)
 
 Factory for the per-column faceted row model. Pass the exported
 `createFacetedRowModel()` or implement your own. Not needed for
@@ -402,7 +402,7 @@ server-side faceting.
 optional facetedUniqueValues: (table, columnId) => () => Map<any, number>;
 ```
 
-Defined in: [types/TableFeatures.ts:236](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L236)
+Defined in: [types/TableFeatures.ts:239](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L239)
 
 Factory for per-column faceted unique values. Pass the exported
 `createFacetedUniqueValues()` or implement your own. Not needed for
@@ -436,7 +436,7 @@ server-side faceting.
 optional filteredRowModel: (table) => () => RowModel<any, any>;
 ```
 
-Defined in: [types/TableFeatures.ts:242](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L242)
+Defined in: [types/TableFeatures.ts:245](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L245)
 
 Factory for the client-side filtered row model. Pass the exported
 `createFilteredRowModel()` or implement your own. Not needed for
@@ -466,7 +466,7 @@ server-side filtering.
 optional filterFns: Record<string, FilterFn<any, any>>;
 ```
 
-Defined in: [types/TableFeatures.ts:254](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L254)
+Defined in: [types/TableFeatures.ts:257](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L257)
 
 Registry of filter functions available to this table by name.
 
@@ -486,7 +486,7 @@ built-in filter function in your bundle.
 optional filterMeta: object;
 ```
 
-Defined in: [types/TableFeatures.ts:266](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L266)
+Defined in: [types/TableFeatures.ts:269](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L269)
 
 Type-only slot for declaring the type of the filter meta that filter
 functions attach to rows via `addMeta` and that is read back from
@@ -520,7 +520,7 @@ Defined in: [features/stockFeatures.ts:27](https://github.com/TanStack/table/blo
 optional groupedRowModel: (table) => () => RowModel<any, any>;
 ```
 
-Defined in: [types/TableFeatures.ts:272](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L272)
+Defined in: [types/TableFeatures.ts:275](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L275)
 
 Factory for the client-side grouped row model. Pass the exported
 `createGroupedRowModel()` or implement your own. Not needed for
@@ -550,7 +550,7 @@ server-side grouping.
 optional paginatedRowModel: (table) => () => RowModel<any, any>;
 ```
 
-Defined in: [types/TableFeatures.ts:278](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L278)
+Defined in: [types/TableFeatures.ts:281](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L281)
 
 Factory for the client-side paginated row model. Pass the exported
 `createPaginatedRowModel()` or implement your own. Not needed for
@@ -664,7 +664,7 @@ Defined in: [features/stockFeatures.ts:32](https://github.com/TanStack/table/blo
 optional sortedRowModel: (table) => () => RowModel<any, any>;
 ```
 
-Defined in: [types/TableFeatures.ts:284](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L284)
+Defined in: [types/TableFeatures.ts:287](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L287)
 
 Factory for the client-side sorted row model. Pass the exported
 `createSortedRowModel()` or implement your own. Not needed for
@@ -694,7 +694,7 @@ server-side sorting.
 optional sortFns: Record<string, SortFn<any, any>>;
 ```
 
-Defined in: [types/TableFeatures.ts:295](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L295)
+Defined in: [types/TableFeatures.ts:298](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L298)
 
 Registry of sorting functions available to this table by name.
 
@@ -713,7 +713,7 @@ sorting function in your bundle.
 optional tableMeta: object;
 ```
 
-Defined in: [types/TableFeatures.ts:305](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L305)
+Defined in: [types/TableFeatures.ts:308](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L308)
 
 Type-only slot for declaring the type of this table's `options.meta`.
 
diff --git a/docs/reference/index/interfaces/TableMeta.md b/docs/reference/index/interfaces/TableMeta.md
index a837e9843b..b3df9ea1d4 100644
--- a/docs/reference/index/interfaces/TableMeta.md
+++ b/docs/reference/index/interfaces/TableMeta.md
@@ -5,7 +5,7 @@ title: TableMeta
 
 # Interface: TableMeta\<TFeatures, TData\>
 
-Defined in: [core/table/coreTablesFeature.types.ts:16](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L16)
+Defined in: [core/table/coreTablesFeature.types.ts:17](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L17)
 
 ## Type Parameters
 
diff --git a/docs/reference/index/interfaces/TableOptions_Core.md b/docs/reference/index/interfaces/TableOptions_Core.md
index 68bb5a4bcb..e3e71d730d 100644
--- a/docs/reference/index/interfaces/TableOptions_Core.md
+++ b/docs/reference/index/interfaces/TableOptions_Core.md
@@ -32,7 +32,7 @@ options are mixed in.
 readonly optional atoms: Partial<{ [K in string | number | symbol]: Atom<ExtractFeatureMapTypes<TFeatures, TableState_FeatureMap>[K]> }>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:108](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L108)
+Defined in: [core/table/coreTablesFeature.types.ts:109](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L109)
 
 Optionally, provide your own external writable atoms for individual state slices.
 When an atom is provided for a given slice, it takes precedence over `options.state[key]`
@@ -52,7 +52,7 @@ model for app-managed table state slices.
 readonly optional autoResetAll: boolean;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:112](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L112)
+Defined in: [core/table/coreTablesFeature.types.ts:113](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L113)
 
 Set this option to override any of the `autoReset...` feature options.
 
@@ -84,7 +84,7 @@ The array of column defs to use for the table.
 readonly data: readonly TData[];
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:116](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L116)
+Defined in: [core/table/coreTablesFeature.types.ts:117](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L117)
 
 The data for the table to display. When the `data` option changes reference, the table will reprocess the data.
 
@@ -116,7 +116,7 @@ Default column options to use for all column defs supplied to the table.
 readonly features: TFeatures & ValidateFeatureSlots<TFeatures>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:100](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L100)
+Defined in: [core/table/coreTablesFeature.types.ts:101](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L101)
 
 The feature modules registered on this table instance.
 
@@ -214,7 +214,7 @@ getSubRows: row => row.subRows
 readonly optional initialState: Partial<ExtractFeatureMapTypes<TFeatures, TableState_FeatureMap>>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:130](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L130)
+Defined in: [core/table/coreTablesFeature.types.ts:131](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L131)
 
 Optionally provide starting values for registered table state slices.
 Feature reset APIs use this value by default, and many reset APIs accept
@@ -233,7 +233,7 @@ object later does not reset table state, so it does not need to be stable.
 readonly optional key: string;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:123](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L123)
+Defined in: [core/table/coreTablesFeature.types.ts:124](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L124)
 
 Optional key used to identify this table instance.
 
@@ -252,7 +252,7 @@ not required unless the table is passed to devtools.
 readonly optional mergeOptions: (defaultOptions, options) => TableOptions<TFeatures, TData>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:134](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L134)
+Defined in: [core/table/coreTablesFeature.types.ts:135](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L135)
 
 This option is used to optionally implement the merging of table options.
 
@@ -282,7 +282,7 @@ This option is used to optionally implement the merging of table options.
 readonly optional meta: ExtractTableMeta<TFeatures, TData>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:144](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L144)
+Defined in: [core/table/coreTablesFeature.types.ts:145](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L145)
 
 You can pass any object to `options.meta` and access it anywhere the `table` is available via `table.options.meta`.
 
@@ -317,7 +317,7 @@ Value used when the desired value is not found in the data.
 readonly optional state: Partial<ExtractFeatureMapTypes<TFeatures, TableState_FeatureMap>>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:152](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L152)
+Defined in: [core/table/coreTablesFeature.types.ts:153](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L153)
 
 Optionally provide externally managed values for individual state slices.
 
diff --git a/docs/reference/index/interfaces/TableOptions_Table.md b/docs/reference/index/interfaces/TableOptions_Table.md
index c01fc9f5b4..8bb8f5c2c2 100644
--- a/docs/reference/index/interfaces/TableOptions_Table.md
+++ b/docs/reference/index/interfaces/TableOptions_Table.md
@@ -5,7 +5,7 @@ title: TableOptions_Table
 
 # Interface: TableOptions\_Table\<TFeatures, TData\>
 
-Defined in: [core/table/coreTablesFeature.types.ts:87](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L87)
+Defined in: [core/table/coreTablesFeature.types.ts:88](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L88)
 
 ## Extended by
 
@@ -29,7 +29,7 @@ Defined in: [core/table/coreTablesFeature.types.ts:87](https://github.com/TanSta
 readonly optional atoms: Partial<{ [K in string | number | symbol]: Atom<ExtractFeatureMapTypes<TFeatures, TableState_FeatureMap>[K]> }>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:108](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L108)
+Defined in: [core/table/coreTablesFeature.types.ts:109](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L109)
 
 Optionally, provide your own external writable atoms for individual state slices.
 When an atom is provided for a given slice, it takes precedence over `options.state[key]`
@@ -45,7 +45,7 @@ model for app-managed table state slices.
 readonly optional autoResetAll: boolean;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:112](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L112)
+Defined in: [core/table/coreTablesFeature.types.ts:113](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L113)
 
 Set this option to override any of the `autoReset...` feature options.
 
@@ -57,7 +57,7 @@ Set this option to override any of the `autoReset...` feature options.
 readonly data: readonly TData[];
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:116](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L116)
+Defined in: [core/table/coreTablesFeature.types.ts:117](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L117)
 
 The data for the table to display. When the `data` option changes reference, the table will reprocess the data.
 
@@ -69,7 +69,7 @@ The data for the table to display. When the `data` option changes reference, the
 readonly features: TFeatures & ValidateFeatureSlots<TFeatures>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:100](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L100)
+Defined in: [core/table/coreTablesFeature.types.ts:101](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L101)
 
 The feature modules registered on this table instance.
 
@@ -87,7 +87,7 @@ slots (`tableMeta`, `columnMeta`).
 readonly optional initialState: Partial<ExtractFeatureMapTypes<TFeatures, TableState_FeatureMap>>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:130](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L130)
+Defined in: [core/table/coreTablesFeature.types.ts:131](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L131)
 
 Optionally provide starting values for registered table state slices.
 Feature reset APIs use this value by default, and many reset APIs accept
@@ -102,7 +102,7 @@ object later does not reset table state, so it does not need to be stable.
 readonly optional key: string;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:123](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L123)
+Defined in: [core/table/coreTablesFeature.types.ts:124](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L124)
 
 Optional key used to identify this table instance.
 
@@ -117,7 +117,7 @@ not required unless the table is passed to devtools.
 readonly optional mergeOptions: (defaultOptions, options) => TableOptions<TFeatures, TData>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:134](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L134)
+Defined in: [core/table/coreTablesFeature.types.ts:135](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L135)
 
 This option is used to optionally implement the merging of table options.
 
@@ -143,7 +143,7 @@ This option is used to optionally implement the merging of table options.
 readonly optional meta: ExtractTableMeta<TFeatures, TData>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:144](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L144)
+Defined in: [core/table/coreTablesFeature.types.ts:145](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L145)
 
 You can pass any object to `options.meta` and access it anywhere the `table` is available via `table.options.meta`.
 
@@ -158,7 +158,7 @@ Declare its type per-table via the `tableMeta` type-only slot on the
 readonly optional state: Partial<ExtractFeatureMapTypes<TFeatures, TableState_FeatureMap>>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:152](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L152)
+Defined in: [core/table/coreTablesFeature.types.ts:153](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L153)
 
 Optionally provide externally managed values for individual state slices.
 
diff --git a/docs/reference/index/interfaces/Table_Core.md b/docs/reference/index/interfaces/Table_Core.md
index 72a2e66a88..bb055303ca 100644
--- a/docs/reference/index/interfaces/Table_Core.md
+++ b/docs/reference/index/interfaces/Table_Core.md
@@ -26,13 +26,53 @@ No features are included.
 
 ## Properties
 
+### \_cellInstanceInitFns?
+
+```ts
+optional _cellInstanceInitFns: <TFeatures, TData, TValue>(cell) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:167](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L167)
+
+Cache of the `initCellInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+##### TValue
+
+`TValue` *extends* `unknown` = `unknown`
+
+#### Parameters
+
+##### cell
+
+[`Cell`](../type-aliases/Cell.md)\<`TFeatures`, `TData`, `TValue`\>
+
+#### Returns
+
+`void`
+
+#### Inherited from
+
+[`Table_Table`](Table_Table.md).[`_cellInstanceInitFns`](Table_Table.md#_cellinstanceinitfns)
+
+***
+
 ### \_cellPrototype?
 
 ```ts
 optional _cellPrototype: object;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:166](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L166)
+Defined in: [core/table/coreTablesFeature.types.ts:173](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L173)
 
 Prototype cache for Cell objects - shared by all cells in this table
 
@@ -42,13 +82,53 @@ Prototype cache for Cell objects - shared by all cells in this table
 
 ***
 
+### \_columnInstanceInitFns?
+
+```ts
+optional _columnInstanceInitFns: <TFeatures, TData, TValue>(column) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:177](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L177)
+
+Cache of the `initColumnInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+##### TValue
+
+`TValue` *extends* `unknown` = `unknown`
+
+#### Parameters
+
+##### column
+
+[`Column`](../type-aliases/Column.md)\<`TFeatures`, `TData`, `TValue`\>
+
+#### Returns
+
+`void`
+
+#### Inherited from
+
+[`Table_Table`](Table_Table.md).[`_columnInstanceInitFns`](Table_Table.md#_columninstanceinitfns)
+
+***
+
 ### \_columnPrototype?
 
 ```ts
 optional _columnPrototype: object;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:170](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L170)
+Defined in: [core/table/coreTablesFeature.types.ts:183](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L183)
 
 Prototype cache for Column objects - shared by all columns in this table
 
@@ -64,7 +144,7 @@ Prototype cache for Column objects - shared by all columns in this table
 readonly _features: Partial<CoreFeatures> & TFeatures;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:174](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L174)
+Defined in: [core/table/coreTablesFeature.types.ts:187](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L187)
 
 The features that are enabled for the table.
 
@@ -74,13 +154,89 @@ The features that are enabled for the table.
 
 ***
 
+### \_headerGroupInstanceInitFns?
+
+```ts
+optional _headerGroupInstanceInitFns: <TFeatures, TData>(headerGroup) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:191](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L191)
+
+Cache of the `initHeaderGroupInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+#### Parameters
+
+##### headerGroup
+
+[`HeaderGroup`](HeaderGroup.md)\<`TFeatures`, `TData`\>
+
+#### Returns
+
+`void`
+
+#### Inherited from
+
+[`Table_Table`](Table_Table.md).[`_headerGroupInstanceInitFns`](Table_Table.md#_headergroupinstanceinitfns)
+
+***
+
+### \_headerInstanceInitFns?
+
+```ts
+optional _headerInstanceInitFns: <TFeatures, TData, TValue>(header) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:197](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L197)
+
+Cache of the `initHeaderInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+##### TValue
+
+`TValue` *extends* `unknown` = `unknown`
+
+#### Parameters
+
+##### header
+
+[`Header`](../type-aliases/Header.md)\<`TFeatures`, `TData`, `TValue`\>
+
+#### Returns
+
+`void`
+
+#### Inherited from
+
+[`Table_Table`](Table_Table.md).[`_headerInstanceInitFns`](Table_Table.md#_headerinstanceinitfns)
+
+***
+
 ### \_headerPrototype?
 
 ```ts
 optional _headerPrototype: object;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:178](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L178)
+Defined in: [core/table/coreTablesFeature.types.ts:203](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L203)
 
 Prototype cache for Header objects - shared by all headers in this table
 
@@ -96,7 +252,7 @@ Prototype cache for Header objects - shared by all headers in this table
 readonly _reactivity: TableReactivityBindings;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:162](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L162)
+Defined in: [core/table/coreTablesFeature.types.ts:163](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L163)
 
 Table reactivity bindings for interacting with TanStack Store.
 
@@ -106,13 +262,49 @@ Table reactivity bindings for interacting with TanStack Store.
 
 ***
 
+### \_rowInstanceInitFns?
+
+```ts
+optional _rowInstanceInitFns: <TFeatures, TData>(row) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:219](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L219)
+
+Cache of the `initRowInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+#### Parameters
+
+##### row
+
+[`Row`](../type-aliases/Row.md)\<`TFeatures`, `TData`\>
+
+#### Returns
+
+`void`
+
+#### Inherited from
+
+[`Table_Table`](Table_Table.md).[`_rowInstanceInitFns`](Table_Table.md#_rowinstanceinitfns)
+
+***
+
 ### \_rowModelFns
 
 ```ts
 readonly _rowModelFns: RowModelFns<TFeatures, TData>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:182](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L182)
+Defined in: [core/table/coreTablesFeature.types.ts:207](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L207)
 
 The row model processing functions that are used to process the data by features.
 
@@ -128,7 +320,7 @@ The row model processing functions that are used to process the data by features
 readonly _rowModels: CachedRowModels<TFeatures, TData>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:186](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L186)
+Defined in: [core/table/coreTablesFeature.types.ts:211](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L211)
 
 The row models that are enabled for the table.
 
@@ -144,7 +336,7 @@ The row models that are enabled for the table.
 optional _rowPrototype: object;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:190](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L190)
+Defined in: [core/table/coreTablesFeature.types.ts:215](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L215)
 
 Prototype cache for Row objects - shared by all rows in this table
 
@@ -160,7 +352,7 @@ Prototype cache for Row objects - shared by all rows in this table
 readonly atoms: Atoms<TFeatures>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:196](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L196)
+Defined in: [core/table/coreTablesFeature.types.ts:225](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L225)
 
 The readonly derived atoms for each `TableState` slice. Each derives from
 its corresponding `baseAtom` plus, optionally, a per-slice external atom or
@@ -178,7 +370,7 @@ external state value (precedence: external atom > external state > base atom).
 readonly baseAtoms: BaseAtoms<TFeatures>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:201](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L201)
+Defined in: [core/table/coreTablesFeature.types.ts:230](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L230)
 
 The internal writable atoms for each `TableState` slice. This is the library's
 single write surface — all state mutations from features land here.
@@ -870,7 +1062,7 @@ Table_RowModels.getSortedRowModel
 readonly initialState: ExtractFeatureMapTypes<TFeatures>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:205](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L205)
+Defined in: [core/table/coreTablesFeature.types.ts:234](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L234)
 
 This is the resolved initial state of the table.
 
@@ -886,7 +1078,7 @@ This is the resolved initial state of the table.
 readonly options: TableOptions<TFeatures, TData>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:209](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L209)
+Defined in: [core/table/coreTablesFeature.types.ts:238](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L238)
 
 A read-only reference to the table's current options.
 
@@ -902,7 +1094,7 @@ A read-only reference to the table's current options.
 readonly optional optionsStore: Atom<TableOptions<TFeatures, TData>>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:215](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L215)
+Defined in: [core/table/coreTablesFeature.types.ts:244](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L244)
 
 Writable atom for table options. Only created when `createOptionsStore` is
 true on the active core reactivity bindings. Adapters that opt out keep
@@ -920,7 +1112,7 @@ options as plain resolved data instead of backing them with an atom.
 reset: () => void;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:235](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L235)
+Defined in: [core/table/coreTablesFeature.types.ts:264](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L264)
 
 Resets the table's internal base atoms to `table.initialState`.
 
@@ -945,7 +1137,7 @@ reset hooks for mutable, transient table-instance data.
 setOptions: (newOptions) => void;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:240](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L240)
+Defined in: [core/table/coreTablesFeature.types.ts:269](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L269)
 
 Updates the table options by applying a value or updater to the current
 resolved options and then merging them through `options.mergeOptions`.
@@ -972,7 +1164,7 @@ resolved options and then merging them through `options.mergeOptions`.
 readonly store: ReadonlyStore<ExtractFeatureMapTypes<TFeatures, TableState_FeatureMap>>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:220](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L220)
+Defined in: [core/table/coreTablesFeature.types.ts:249](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L249)
 
 The readonly flat store for the table state. Derives from `table.atoms`
 only; never reads external state directly.
diff --git a/docs/reference/index/interfaces/Table_CoreProperties.md b/docs/reference/index/interfaces/Table_CoreProperties.md
index 32d3310b72..322a1130b6 100644
--- a/docs/reference/index/interfaces/Table_CoreProperties.md
+++ b/docs/reference/index/interfaces/Table_CoreProperties.md
@@ -5,7 +5,7 @@ title: Table_CoreProperties
 
 # Interface: Table\_CoreProperties\<TFeatures, TData\>
 
-Defined in: [core/table/coreTablesFeature.types.ts:155](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L155)
+Defined in: [core/table/coreTablesFeature.types.ts:156](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L156)
 
 ## Extended by
 
@@ -23,25 +23,97 @@ Defined in: [core/table/coreTablesFeature.types.ts:155](https://github.com/TanSt
 
 ## Properties
 
+### \_cellInstanceInitFns?
+
+```ts
+optional _cellInstanceInitFns: <TFeatures, TData, TValue>(cell) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:167](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L167)
+
+Cache of the `initCellInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+##### TValue
+
+`TValue` *extends* `unknown` = `unknown`
+
+#### Parameters
+
+##### cell
+
+[`Cell`](../type-aliases/Cell.md)\<`TFeatures`, `TData`, `TValue`\>
+
+#### Returns
+
+`void`
+
+***
+
 ### \_cellPrototype?
 
 ```ts
 optional _cellPrototype: object;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:166](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L166)
+Defined in: [core/table/coreTablesFeature.types.ts:173](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L173)
 
 Prototype cache for Cell objects - shared by all cells in this table
 
 ***
 
+### \_columnInstanceInitFns?
+
+```ts
+optional _columnInstanceInitFns: <TFeatures, TData, TValue>(column) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:177](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L177)
+
+Cache of the `initColumnInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+##### TValue
+
+`TValue` *extends* `unknown` = `unknown`
+
+#### Parameters
+
+##### column
+
+[`Column`](../type-aliases/Column.md)\<`TFeatures`, `TData`, `TValue`\>
+
+#### Returns
+
+`void`
+
+***
+
 ### \_columnPrototype?
 
 ```ts
 optional _columnPrototype: object;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:170](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L170)
+Defined in: [core/table/coreTablesFeature.types.ts:183](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L183)
 
 Prototype cache for Column objects - shared by all columns in this table
 
@@ -53,19 +125,87 @@ Prototype cache for Column objects - shared by all columns in this table
 readonly _features: Partial<CoreFeatures> & TFeatures;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:174](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L174)
+Defined in: [core/table/coreTablesFeature.types.ts:187](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L187)
 
 The features that are enabled for the table.
 
 ***
 
+### \_headerGroupInstanceInitFns?
+
+```ts
+optional _headerGroupInstanceInitFns: <TFeatures, TData>(headerGroup) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:191](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L191)
+
+Cache of the `initHeaderGroupInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+#### Parameters
+
+##### headerGroup
+
+[`HeaderGroup`](HeaderGroup.md)\<`TFeatures`, `TData`\>
+
+#### Returns
+
+`void`
+
+***
+
+### \_headerInstanceInitFns?
+
+```ts
+optional _headerInstanceInitFns: <TFeatures, TData, TValue>(header) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:197](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L197)
+
+Cache of the `initHeaderInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+##### TValue
+
+`TValue` *extends* `unknown` = `unknown`
+
+#### Parameters
+
+##### header
+
+[`Header`](../type-aliases/Header.md)\<`TFeatures`, `TData`, `TValue`\>
+
+#### Returns
+
+`void`
+
+***
+
 ### \_headerPrototype?
 
 ```ts
 optional _headerPrototype: object;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:178](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L178)
+Defined in: [core/table/coreTablesFeature.types.ts:203](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L203)
 
 Prototype cache for Header objects - shared by all headers in this table
 
@@ -77,19 +217,51 @@ Prototype cache for Header objects - shared by all headers in this table
 readonly _reactivity: TableReactivityBindings;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:162](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L162)
+Defined in: [core/table/coreTablesFeature.types.ts:163](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L163)
 
 Table reactivity bindings for interacting with TanStack Store.
 
 ***
 
+### \_rowInstanceInitFns?
+
+```ts
+optional _rowInstanceInitFns: <TFeatures, TData>(row) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:219](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L219)
+
+Cache of the `initRowInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+#### Parameters
+
+##### row
+
+[`Row`](../type-aliases/Row.md)\<`TFeatures`, `TData`\>
+
+#### Returns
+
+`void`
+
+***
+
 ### \_rowModelFns
 
 ```ts
 readonly _rowModelFns: RowModelFns<TFeatures, TData>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:182](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L182)
+Defined in: [core/table/coreTablesFeature.types.ts:207](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L207)
 
 The row model processing functions that are used to process the data by features.
 
@@ -101,7 +273,7 @@ The row model processing functions that are used to process the data by features
 readonly _rowModels: CachedRowModels<TFeatures, TData>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:186](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L186)
+Defined in: [core/table/coreTablesFeature.types.ts:211](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L211)
 
 The row models that are enabled for the table.
 
@@ -113,7 +285,7 @@ The row models that are enabled for the table.
 optional _rowPrototype: object;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:190](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L190)
+Defined in: [core/table/coreTablesFeature.types.ts:215](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L215)
 
 Prototype cache for Row objects - shared by all rows in this table
 
@@ -125,7 +297,7 @@ Prototype cache for Row objects - shared by all rows in this table
 readonly atoms: Atoms<TFeatures>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:196](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L196)
+Defined in: [core/table/coreTablesFeature.types.ts:225](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L225)
 
 The readonly derived atoms for each `TableState` slice. Each derives from
 its corresponding `baseAtom` plus, optionally, a per-slice external atom or
@@ -139,7 +311,7 @@ external state value (precedence: external atom > external state > base atom).
 readonly baseAtoms: BaseAtoms<TFeatures>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:201](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L201)
+Defined in: [core/table/coreTablesFeature.types.ts:230](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L230)
 
 The internal writable atoms for each `TableState` slice. This is the library's
 single write surface — all state mutations from features land here.
@@ -152,7 +324,7 @@ single write surface — all state mutations from features land here.
 readonly initialState: ExtractFeatureMapTypes<TFeatures>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:205](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L205)
+Defined in: [core/table/coreTablesFeature.types.ts:234](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L234)
 
 This is the resolved initial state of the table.
 
@@ -164,7 +336,7 @@ This is the resolved initial state of the table.
 readonly options: TableOptions<TFeatures, TData>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:209](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L209)
+Defined in: [core/table/coreTablesFeature.types.ts:238](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L238)
 
 A read-only reference to the table's current options.
 
@@ -176,7 +348,7 @@ A read-only reference to the table's current options.
 readonly optional optionsStore: Atom<TableOptions<TFeatures, TData>>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:215](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L215)
+Defined in: [core/table/coreTablesFeature.types.ts:244](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L244)
 
 Writable atom for table options. Only created when `createOptionsStore` is
 true on the active core reactivity bindings. Adapters that opt out keep
@@ -190,7 +362,7 @@ options as plain resolved data instead of backing them with an atom.
 readonly store: ReadonlyStore<ExtractFeatureMapTypes<TFeatures, TableState_FeatureMap>>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:220](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L220)
+Defined in: [core/table/coreTablesFeature.types.ts:249](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L249)
 
 The readonly flat store for the table state. Derives from `table.atoms`
 only; never reads external state directly.
diff --git a/docs/reference/index/interfaces/Table_Internal.md b/docs/reference/index/interfaces/Table_Internal.md
index 1e9f33a695..9fd49471da 100644
--- a/docs/reference/index/interfaces/Table_Internal.md
+++ b/docs/reference/index/interfaces/Table_Internal.md
@@ -25,13 +25,55 @@ Internal broad table shape used by feature implementations.
 
 ## Properties
 
+### \_cellInstanceInitFns?
+
+```ts
+optional _cellInstanceInitFns: <TFeatures, TData, TValue>(cell) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:167](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L167)
+
+Cache of the `initCellInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+##### TValue
+
+`TValue` *extends* `unknown` = `unknown`
+
+#### Parameters
+
+##### cell
+
+[`Cell`](../type-aliases/Cell.md)\<`TFeatures`, `TData`, `TValue`\>
+
+#### Returns
+
+`void`
+
+#### Inherited from
+
+```ts
+Omit._cellInstanceInitFns
+```
+
+***
+
 ### \_cellPrototype?
 
 ```ts
 optional _cellPrototype: object;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:166](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L166)
+Defined in: [core/table/coreTablesFeature.types.ts:173](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L173)
 
 Prototype cache for Cell objects - shared by all cells in this table
 
@@ -41,13 +83,55 @@ Prototype cache for Cell objects - shared by all cells in this table
 
 ***
 
+### \_columnInstanceInitFns?
+
+```ts
+optional _columnInstanceInitFns: <TFeatures, TData, TValue>(column) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:177](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L177)
+
+Cache of the `initColumnInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+##### TValue
+
+`TValue` *extends* `unknown` = `unknown`
+
+#### Parameters
+
+##### column
+
+[`Column`](../type-aliases/Column.md)\<`TFeatures`, `TData`, `TValue`\>
+
+#### Returns
+
+`void`
+
+#### Inherited from
+
+```ts
+Omit._columnInstanceInitFns
+```
+
+***
+
 ### \_columnPrototype?
 
 ```ts
 optional _columnPrototype: object;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:170](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L170)
+Defined in: [core/table/coreTablesFeature.types.ts:183](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L183)
 
 Prototype cache for Column objects - shared by all columns in this table
 
@@ -63,7 +147,7 @@ Prototype cache for Column objects - shared by all columns in this table
 readonly _features: Partial<CoreFeatures> & TFeatures;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:174](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L174)
+Defined in: [core/table/coreTablesFeature.types.ts:187](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L187)
 
 The features that are enabled for the table.
 
@@ -75,13 +159,93 @@ Omit._features
 
 ***
 
+### \_headerGroupInstanceInitFns?
+
+```ts
+optional _headerGroupInstanceInitFns: <TFeatures, TData>(headerGroup) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:191](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L191)
+
+Cache of the `initHeaderGroupInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+#### Parameters
+
+##### headerGroup
+
+[`HeaderGroup`](HeaderGroup.md)\<`TFeatures`, `TData`\>
+
+#### Returns
+
+`void`
+
+#### Inherited from
+
+```ts
+Omit._headerGroupInstanceInitFns
+```
+
+***
+
+### \_headerInstanceInitFns?
+
+```ts
+optional _headerInstanceInitFns: <TFeatures, TData, TValue>(header) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:197](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L197)
+
+Cache of the `initHeaderInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+##### TValue
+
+`TValue` *extends* `unknown` = `unknown`
+
+#### Parameters
+
+##### header
+
+[`Header`](../type-aliases/Header.md)\<`TFeatures`, `TData`, `TValue`\>
+
+#### Returns
+
+`void`
+
+#### Inherited from
+
+```ts
+Omit._headerInstanceInitFns
+```
+
+***
+
 ### \_headerPrototype?
 
 ```ts
 optional _headerPrototype: object;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:178](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L178)
+Defined in: [core/table/coreTablesFeature.types.ts:203](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L203)
 
 Prototype cache for Header objects - shared by all headers in this table
 
@@ -97,7 +261,7 @@ Prototype cache for Header objects - shared by all headers in this table
 readonly _reactivity: TableReactivityBindings;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:162](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L162)
+Defined in: [core/table/coreTablesFeature.types.ts:163](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L163)
 
 Table reactivity bindings for interacting with TanStack Store.
 
@@ -107,6 +271,44 @@ Table reactivity bindings for interacting with TanStack Store.
 
 ***
 
+### \_rowInstanceInitFns?
+
+```ts
+optional _rowInstanceInitFns: <TFeatures, TData>(row) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:219](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L219)
+
+Cache of the `initRowInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+#### Parameters
+
+##### row
+
+[`Row`](../type-aliases/Row.md)\<`TFeatures`, `TData`\>
+
+#### Returns
+
+`void`
+
+#### Inherited from
+
+```ts
+Omit._rowInstanceInitFns
+```
+
+***
+
 ### \_rowModelFns
 
 ```ts
@@ -133,7 +335,7 @@ Defined in: [types/Table.ts:104](https://github.com/TanStack/table/blob/main/pac
 optional _rowPrototype: object;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:190](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L190)
+Defined in: [core/table/coreTablesFeature.types.ts:215](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L215)
 
 Prototype cache for Row objects - shared by all rows in this table
 
@@ -961,7 +1163,7 @@ optional state: TableState_All;
 readonly optional optionsStore: Atom<TableOptions<TFeatures, TData>>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:215](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L215)
+Defined in: [core/table/coreTablesFeature.types.ts:244](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L244)
 
 Writable atom for table options. Only created when `createOptionsStore` is
 true on the active core reactivity bindings. Adapters that opt out keep
@@ -981,7 +1183,7 @@ Omit.optionsStore
 reset: () => void;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:235](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L235)
+Defined in: [core/table/coreTablesFeature.types.ts:264](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L264)
 
 Resets the table's internal base atoms to `table.initialState`.
 
@@ -1008,7 +1210,7 @@ Omit.reset
 setOptions: (newOptions) => void;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:240](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L240)
+Defined in: [core/table/coreTablesFeature.types.ts:269](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L269)
 
 Updates the table options by applying a value or updater to the current
 resolved options and then merging them through `options.mergeOptions`.
diff --git a/docs/reference/index/interfaces/Table_Table.md b/docs/reference/index/interfaces/Table_Table.md
index 438262fb77..edc13ea2c3 100644
--- a/docs/reference/index/interfaces/Table_Table.md
+++ b/docs/reference/index/interfaces/Table_Table.md
@@ -5,7 +5,7 @@ title: Table_Table
 
 # Interface: Table\_Table\<TFeatures, TData\>
 
-Defined in: [core/table/coreTablesFeature.types.ts:223](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L223)
+Defined in: [core/table/coreTablesFeature.types.ts:252](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L252)
 
 ## Extends
 
@@ -27,13 +27,53 @@ Defined in: [core/table/coreTablesFeature.types.ts:223](https://github.com/TanSt
 
 ## Properties
 
+### \_cellInstanceInitFns?
+
+```ts
+optional _cellInstanceInitFns: <TFeatures, TData, TValue>(cell) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:167](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L167)
+
+Cache of the `initCellInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+##### TValue
+
+`TValue` *extends* `unknown` = `unknown`
+
+#### Parameters
+
+##### cell
+
+[`Cell`](../type-aliases/Cell.md)\<`TFeatures`, `TData`, `TValue`\>
+
+#### Returns
+
+`void`
+
+#### Inherited from
+
+[`Table_CoreProperties`](Table_CoreProperties.md).[`_cellInstanceInitFns`](Table_CoreProperties.md#_cellinstanceinitfns)
+
+***
+
 ### \_cellPrototype?
 
 ```ts
 optional _cellPrototype: object;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:166](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L166)
+Defined in: [core/table/coreTablesFeature.types.ts:173](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L173)
 
 Prototype cache for Cell objects - shared by all cells in this table
 
@@ -43,13 +83,53 @@ Prototype cache for Cell objects - shared by all cells in this table
 
 ***
 
+### \_columnInstanceInitFns?
+
+```ts
+optional _columnInstanceInitFns: <TFeatures, TData, TValue>(column) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:177](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L177)
+
+Cache of the `initColumnInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+##### TValue
+
+`TValue` *extends* `unknown` = `unknown`
+
+#### Parameters
+
+##### column
+
+[`Column`](../type-aliases/Column.md)\<`TFeatures`, `TData`, `TValue`\>
+
+#### Returns
+
+`void`
+
+#### Inherited from
+
+[`Table_CoreProperties`](Table_CoreProperties.md).[`_columnInstanceInitFns`](Table_CoreProperties.md#_columninstanceinitfns)
+
+***
+
 ### \_columnPrototype?
 
 ```ts
 optional _columnPrototype: object;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:170](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L170)
+Defined in: [core/table/coreTablesFeature.types.ts:183](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L183)
 
 Prototype cache for Column objects - shared by all columns in this table
 
@@ -65,7 +145,7 @@ Prototype cache for Column objects - shared by all columns in this table
 readonly _features: Partial<CoreFeatures> & TFeatures;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:174](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L174)
+Defined in: [core/table/coreTablesFeature.types.ts:187](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L187)
 
 The features that are enabled for the table.
 
@@ -75,13 +155,89 @@ The features that are enabled for the table.
 
 ***
 
+### \_headerGroupInstanceInitFns?
+
+```ts
+optional _headerGroupInstanceInitFns: <TFeatures, TData>(headerGroup) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:191](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L191)
+
+Cache of the `initHeaderGroupInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+#### Parameters
+
+##### headerGroup
+
+[`HeaderGroup`](HeaderGroup.md)\<`TFeatures`, `TData`\>
+
+#### Returns
+
+`void`
+
+#### Inherited from
+
+[`Table_CoreProperties`](Table_CoreProperties.md).[`_headerGroupInstanceInitFns`](Table_CoreProperties.md#_headergroupinstanceinitfns)
+
+***
+
+### \_headerInstanceInitFns?
+
+```ts
+optional _headerInstanceInitFns: <TFeatures, TData, TValue>(header) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:197](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L197)
+
+Cache of the `initHeaderInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+##### TValue
+
+`TValue` *extends* `unknown` = `unknown`
+
+#### Parameters
+
+##### header
+
+[`Header`](../type-aliases/Header.md)\<`TFeatures`, `TData`, `TValue`\>
+
+#### Returns
+
+`void`
+
+#### Inherited from
+
+[`Table_CoreProperties`](Table_CoreProperties.md).[`_headerInstanceInitFns`](Table_CoreProperties.md#_headerinstanceinitfns)
+
+***
+
 ### \_headerPrototype?
 
 ```ts
 optional _headerPrototype: object;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:178](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L178)
+Defined in: [core/table/coreTablesFeature.types.ts:203](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L203)
 
 Prototype cache for Header objects - shared by all headers in this table
 
@@ -97,7 +253,7 @@ Prototype cache for Header objects - shared by all headers in this table
 readonly _reactivity: TableReactivityBindings;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:162](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L162)
+Defined in: [core/table/coreTablesFeature.types.ts:163](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L163)
 
 Table reactivity bindings for interacting with TanStack Store.
 
@@ -107,13 +263,49 @@ Table reactivity bindings for interacting with TanStack Store.
 
 ***
 
+### \_rowInstanceInitFns?
+
+```ts
+optional _rowInstanceInitFns: <TFeatures, TData>(row) => void[];
+```
+
+Defined in: [core/table/coreTablesFeature.types.ts:219](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L219)
+
+Cache of the `initRowInstanceData` functions for features that define one.
+
+#### Type Parameters
+
+##### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](TableFeatures.md)
+
+##### TData
+
+`TData` *extends* [`RowData`](../type-aliases/RowData.md)
+
+#### Parameters
+
+##### row
+
+[`Row`](../type-aliases/Row.md)\<`TFeatures`, `TData`\>
+
+#### Returns
+
+`void`
+
+#### Inherited from
+
+[`Table_CoreProperties`](Table_CoreProperties.md).[`_rowInstanceInitFns`](Table_CoreProperties.md#_rowinstanceinitfns)
+
+***
+
 ### \_rowModelFns
 
 ```ts
 readonly _rowModelFns: RowModelFns<TFeatures, TData>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:182](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L182)
+Defined in: [core/table/coreTablesFeature.types.ts:207](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L207)
 
 The row model processing functions that are used to process the data by features.
 
@@ -129,7 +321,7 @@ The row model processing functions that are used to process the data by features
 readonly _rowModels: CachedRowModels<TFeatures, TData>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:186](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L186)
+Defined in: [core/table/coreTablesFeature.types.ts:211](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L211)
 
 The row models that are enabled for the table.
 
@@ -145,7 +337,7 @@ The row models that are enabled for the table.
 optional _rowPrototype: object;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:190](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L190)
+Defined in: [core/table/coreTablesFeature.types.ts:215](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L215)
 
 Prototype cache for Row objects - shared by all rows in this table
 
@@ -161,7 +353,7 @@ Prototype cache for Row objects - shared by all rows in this table
 readonly atoms: Atoms<TFeatures>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:196](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L196)
+Defined in: [core/table/coreTablesFeature.types.ts:225](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L225)
 
 The readonly derived atoms for each `TableState` slice. Each derives from
 its corresponding `baseAtom` plus, optionally, a per-slice external atom or
@@ -179,7 +371,7 @@ external state value (precedence: external atom > external state > base atom).
 readonly baseAtoms: BaseAtoms<TFeatures>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:201](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L201)
+Defined in: [core/table/coreTablesFeature.types.ts:230](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L230)
 
 The internal writable atoms for each `TableState` slice. This is the library's
 single write surface — all state mutations from features land here.
@@ -196,7 +388,7 @@ single write surface — all state mutations from features land here.
 readonly initialState: ExtractFeatureMapTypes<TFeatures>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:205](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L205)
+Defined in: [core/table/coreTablesFeature.types.ts:234](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L234)
 
 This is the resolved initial state of the table.
 
@@ -212,7 +404,7 @@ This is the resolved initial state of the table.
 readonly options: TableOptions<TFeatures, TData>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:209](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L209)
+Defined in: [core/table/coreTablesFeature.types.ts:238](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L238)
 
 A read-only reference to the table's current options.
 
@@ -228,7 +420,7 @@ A read-only reference to the table's current options.
 readonly optional optionsStore: Atom<TableOptions<TFeatures, TData>>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:215](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L215)
+Defined in: [core/table/coreTablesFeature.types.ts:244](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L244)
 
 Writable atom for table options. Only created when `createOptionsStore` is
 true on the active core reactivity bindings. Adapters that opt out keep
@@ -246,7 +438,7 @@ options as plain resolved data instead of backing them with an atom.
 reset: () => void;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:235](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L235)
+Defined in: [core/table/coreTablesFeature.types.ts:264](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L264)
 
 Resets the table's internal base atoms to `table.initialState`.
 
@@ -267,7 +459,7 @@ reset hooks for mutable, transient table-instance data.
 setOptions: (newOptions) => void;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:240](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L240)
+Defined in: [core/table/coreTablesFeature.types.ts:269](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L269)
 
 Updates the table options by applying a value or updater to the current
 resolved options and then merging them through `options.mergeOptions`.
@@ -290,7 +482,7 @@ resolved options and then merging them through `options.mergeOptions`.
 readonly store: ReadonlyStore<ExtractFeatureMapTypes<TFeatures, TableState_FeatureMap>>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:220](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L220)
+Defined in: [core/table/coreTablesFeature.types.ts:249](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L249)
 
 The readonly flat store for the table state. Derives from `table.atoms`
 only; never reads external state directly.
diff --git a/docs/reference/index/type-aliases/Atoms.md b/docs/reference/index/type-aliases/Atoms.md
index aa6927e161..a31812282d 100644
--- a/docs/reference/index/type-aliases/Atoms.md
+++ b/docs/reference/index/type-aliases/Atoms.md
@@ -9,7 +9,7 @@ title: Atoms
 type Atoms<TFeatures> = { [K in keyof TableState<TFeatures>]-?: ReadonlyAtom<TableState<TFeatures>[K]> };
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:54](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L54)
+Defined in: [core/table/coreTablesFeature.types.ts:55](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L55)
 
 A map of readonly derived atoms, one per `TableState` slice. Each derives
 from its corresponding `baseAtom` plus, optionally, a per-slice external
diff --git a/docs/reference/index/type-aliases/Atoms_All.md b/docs/reference/index/type-aliases/Atoms_All.md
index dd42c9523e..c965cc6dd6 100644
--- a/docs/reference/index/type-aliases/Atoms_All.md
+++ b/docs/reference/index/type-aliases/Atoms_All.md
@@ -9,4 +9,4 @@ title: Atoms_All
 type Atoms_All = { [K in keyof TableState_All]?: ReadonlyAtom<TableState_All[K]> };
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:80](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L80)
+Defined in: [core/table/coreTablesFeature.types.ts:81](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L81)
diff --git a/docs/reference/index/type-aliases/BaseAtoms.md b/docs/reference/index/type-aliases/BaseAtoms.md
index bee16972f8..e24d1c7707 100644
--- a/docs/reference/index/type-aliases/BaseAtoms.md
+++ b/docs/reference/index/type-aliases/BaseAtoms.md
@@ -9,7 +9,7 @@ title: BaseAtoms
 type BaseAtoms<TFeatures> = { [K in keyof TableState<TFeatures>]-?: Atom<TableState<TFeatures>[K]> };
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:43](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L43)
+Defined in: [core/table/coreTablesFeature.types.ts:44](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L44)
 
 A map of writable atoms, one per `TableState` slice. These are the internal
 writable atoms that the library always writes to via `makeStateUpdater`.
diff --git a/docs/reference/index/type-aliases/BaseAtoms_All.md b/docs/reference/index/type-aliases/BaseAtoms_All.md
index ffbdadd9b8..9bef86d951 100644
--- a/docs/reference/index/type-aliases/BaseAtoms_All.md
+++ b/docs/reference/index/type-aliases/BaseAtoms_All.md
@@ -9,7 +9,7 @@ title: BaseAtoms_All
 type BaseAtoms_All = { [K in keyof TableState_All]?: Atom<Exclude<TableState_All[K], undefined>> };
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:77](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L77)
+Defined in: [core/table/coreTablesFeature.types.ts:78](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L78)
 
 Internal "all features" flat variants of the atom types. `Table_Internal`
 uses these so feature code (written generically over `TFeatures`) can access
diff --git a/docs/reference/index/type-aliases/BuiltInAggregationFn.md b/docs/reference/index/type-aliases/BuiltInAggregationFn.md
index c131b526fb..9c567e4f25 100644
--- a/docs/reference/index/type-aliases/BuiltInAggregationFn.md
+++ b/docs/reference/index/type-aliases/BuiltInAggregationFn.md
@@ -9,4 +9,4 @@ title: BuiltInAggregationFn
 type BuiltInAggregationFn = keyof typeof aggregationFns;
 ```
 
-Defined in: [features/row-aggregation/aggregationFns.ts:345](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L345)
+Defined in: [features/row-aggregation/aggregationFns.ts:383](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L383)
diff --git a/docs/reference/index/type-aliases/ColumnDefResolved.md b/docs/reference/index/type-aliases/ColumnDefResolved.md
index 6ae3d58e84..0dfa25fb6c 100644
--- a/docs/reference/index/type-aliases/ColumnDefResolved.md
+++ b/docs/reference/index/type-aliases/ColumnDefResolved.md
@@ -16,7 +16,7 @@ Defined in: [types/ColumnDef.ts:252](https://github.com/TanStack/table/blob/main
 ### accessorKey?
 
 ```ts
-optional accessorKey: string;
+optional accessorKey: string & object | keyof TData;
 ```
 
 ## Type Parameters
diff --git a/docs/reference/index/type-aliases/DeepValue.md b/docs/reference/index/type-aliases/DeepValue.md
index 4101923fb3..e268f6dd83 100644
--- a/docs/reference/index/type-aliases/DeepValue.md
+++ b/docs/reference/index/type-aliases/DeepValue.md
@@ -6,7 +6,7 @@ title: DeepValue
 # Type Alias: DeepValue\<T, TProp\>
 
 ```ts
-type DeepValue<T, TProp> = T extends Record<string | number, any> ? TProp extends `${infer TBranch}.${infer TDeepProp}` ? DeepValue<T[TBranch], TDeepProp> : T[TProp & string] : never;
+type DeepValue<T, TProp> = T extends Record<string | number, any> ? TProp extends `${infer TBranch}.${infer TDeepProp}` ? DeepValue<T[TBranch], TDeepProp> : T[TProp & keyof T] : never;
 ```
 
 Defined in: [types/type-utils.ts:79](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/type-utils.ts#L79)
diff --git a/docs/reference/index/type-aliases/ExternalAtoms.md b/docs/reference/index/type-aliases/ExternalAtoms.md
index 9ca299caf4..1de06a4f69 100644
--- a/docs/reference/index/type-aliases/ExternalAtoms.md
+++ b/docs/reference/index/type-aliases/ExternalAtoms.md
@@ -9,7 +9,7 @@ title: ExternalAtoms
 type ExternalAtoms<TFeatures> = Partial<{ [K in keyof TableState<TFeatures>]: Atom<TableState<TFeatures>[K]> }>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:63](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L63)
+Defined in: [core/table/coreTablesFeature.types.ts:64](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L64)
 
 A map of optional external atoms, one per `TableState` slice. Consumers can
 provide their own writable atom for any state slice to take over ownership
diff --git a/docs/reference/index/type-aliases/ExternalAtoms_All.md b/docs/reference/index/type-aliases/ExternalAtoms_All.md
index 3c755c1df8..450fc7a09c 100644
--- a/docs/reference/index/type-aliases/ExternalAtoms_All.md
+++ b/docs/reference/index/type-aliases/ExternalAtoms_All.md
@@ -9,4 +9,4 @@ title: ExternalAtoms_All
 type ExternalAtoms_All = Partial<{ [K in keyof TableState_All]: Atom<Exclude<TableState_All[K], undefined>> }>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:83](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L83)
+Defined in: [core/table/coreTablesFeature.types.ts:84](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L84)
diff --git a/docs/reference/index/type-aliases/ExtractFeatureMapTypes.md b/docs/reference/index/type-aliases/ExtractFeatureMapTypes.md
index 70557c8a8c..7914800d23 100644
--- a/docs/reference/index/type-aliases/ExtractFeatureMapTypes.md
+++ b/docs/reference/index/type-aliases/ExtractFeatureMapTypes.md
@@ -9,7 +9,7 @@ title: ExtractFeatureMapTypes
 type ExtractFeatureMapTypes<TFeatures, TFeatureMap> = IsAny<TFeatures> extends true ? UnionToIntersection<TFeatureMap[keyof TFeatureMap]> : UnionToIntersectionOrEmpty<TFeatureMap[Extract<keyof TFeatures, keyof TFeatureMap>]>;
 ```
 
-Defined in: [types/TableFeatures.ts:40](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L40)
+Defined in: [types/TableFeatures.ts:43](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L43)
 
 Extracts the API/types contributed by the features present in `TFeatures`.
 
diff --git a/docs/reference/index/type-aliases/ExtractTableMeta.md b/docs/reference/index/type-aliases/ExtractTableMeta.md
index 1e9467217d..84f7e47859 100644
--- a/docs/reference/index/type-aliases/ExtractTableMeta.md
+++ b/docs/reference/index/type-aliases/ExtractTableMeta.md
@@ -9,7 +9,7 @@ title: ExtractTableMeta
 type ExtractTableMeta<TFeatures, TData> = IsAny<TFeatures> extends true ? TableMeta<TFeatures, TData> : TFeatures extends object ? TMeta : TableMeta<TFeatures, TData>;
 ```
 
-Defined in: [core/table/coreTablesFeature.types.ts:29](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L29)
+Defined in: [core/table/coreTablesFeature.types.ts:30](https://github.com/TanStack/table/blob/main/packages/table-core/src/core/table/coreTablesFeature.types.ts#L30)
 
 Resolves the type of `options.meta` for a feature set.
 
diff --git a/docs/reference/index/type-aliases/IsAny.md b/docs/reference/index/type-aliases/IsAny.md
index b9b8472890..d678b2a712 100644
--- a/docs/reference/index/type-aliases/IsAny.md
+++ b/docs/reference/index/type-aliases/IsAny.md
@@ -9,7 +9,7 @@ title: IsAny
 type IsAny<T> = 0 extends 1 & T ? true : false;
 ```
 
-Defined in: [types/TableFeatures.ts:21](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L21)
+Defined in: [types/TableFeatures.ts:24](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L24)
 
 Detects whether a type is `any`.
 
diff --git a/docs/reference/index/type-aliases/NonFeatureKeys.md b/docs/reference/index/type-aliases/NonFeatureKeys.md
index 5d21738c74..bb449cf7bb 100644
--- a/docs/reference/index/type-aliases/NonFeatureKeys.md
+++ b/docs/reference/index/type-aliases/NonFeatureKeys.md
@@ -24,7 +24,7 @@ type NonFeatureKeys =
   | "tableMeta";
 ```
 
-Defined in: [types/TableFeatures.ts:67](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L67)
+Defined in: [types/TableFeatures.ts:70](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L70)
 
 Keys of the `features` option that are not table features themselves.
 
diff --git a/docs/reference/index/type-aliases/ValidateFeatureSlots.md b/docs/reference/index/type-aliases/ValidateFeatureSlots.md
index d81d981cca..472bee7a19 100644
--- a/docs/reference/index/type-aliases/ValidateFeatureSlots.md
+++ b/docs/reference/index/type-aliases/ValidateFeatureSlots.md
@@ -9,7 +9,7 @@ title: ValidateFeatureSlots
 type ValidateFeatureSlots<TFeatures> = IsAny<TFeatures> extends true ? object : { [K in keyof TFeatures as K extends keyof FeatureSlotPrereqs ? K : never]: K extends keyof FeatureSlotPrereqs ? [Extract<FeatureSlotPrereqs[K], keyof TFeatures>] extends [never] ? `Error: '${K & string}' requires '${FeatureSlotPrereqs[K] & string}' to be included in this table's features.` : TFeatures[K] : never };
 ```
 
-Defined in: [types/TableFeatures.ts:158](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L158)
+Defined in: [types/TableFeatures.ts:161](https://github.com/TanStack/table/blob/main/packages/table-core/src/types/TableFeatures.ts#L161)
 
 Validates that every row model and fn registry slot in a features object is
 accompanied by its prerequisite feature.
diff --git a/docs/reference/index/variables/aggregationFn_count.md b/docs/reference/index/variables/aggregationFn_count.md
index 871b9797b6..ffe5518993 100644
--- a/docs/reference/index/variables/aggregationFn_count.md
+++ b/docs/reference/index/variables/aggregationFn_count.md
@@ -9,6 +9,6 @@ title: aggregationFn_count
 const aggregationFn_count: AggregationFnDef<any, any, unknown, number>;
 ```
 
-Defined in: [features/row-aggregation/aggregationFns.ts:282](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L282)
+Defined in: [features/row-aggregation/aggregationFns.ts:320](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L320)
 
 Counts rows, independently of the column's values.
diff --git a/docs/reference/index/variables/aggregationFn_extent.md b/docs/reference/index/variables/aggregationFn_extent.md
index e0763c9907..a4a5ac40eb 100644
--- a/docs/reference/index/variables/aggregationFn_extent.md
+++ b/docs/reference/index/variables/aggregationFn_extent.md
@@ -9,7 +9,7 @@ title: aggregationFn_extent
 const aggregationFn_extent: AggregationFnDef<any, any, unknown, [RangeValue | undefined, RangeValue | undefined]>;
 ```
 
-Defined in: [features/row-aggregation/aggregationFns.ts:146](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L146)
+Defined in: [features/row-aggregation/aggregationFns.ts:162](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L162)
 
 Finds the minimum and maximum numeric or Date values from the selected rows.
 Empty inputs return
diff --git a/docs/reference/index/variables/aggregationFn_first.md b/docs/reference/index/variables/aggregationFn_first.md
index ff2356dd7e..66db8bc2ca 100644
--- a/docs/reference/index/variables/aggregationFn_first.md
+++ b/docs/reference/index/variables/aggregationFn_first.md
@@ -9,6 +9,6 @@ title: aggregationFn_first
 const aggregationFn_first: AggregationFnDef<any, any, unknown, unknown>;
 ```
 
-Defined in: [features/row-aggregation/aggregationFns.ts:300](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L300)
+Defined in: [features/row-aggregation/aggregationFns.ts:338](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L338)
 
 Returns the first row's value, including a nullish value.
diff --git a/docs/reference/index/variables/aggregationFn_last.md b/docs/reference/index/variables/aggregationFn_last.md
index 4dda251314..a6dec5e830 100644
--- a/docs/reference/index/variables/aggregationFn_last.md
+++ b/docs/reference/index/variables/aggregationFn_last.md
@@ -9,6 +9,6 @@ title: aggregationFn_last
 const aggregationFn_last: AggregationFnDef<any, any, unknown, unknown>;
 ```
 
-Defined in: [features/row-aggregation/aggregationFns.ts:312](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L312)
+Defined in: [features/row-aggregation/aggregationFns.ts:350](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L350)
 
 Returns the last row's value, including a nullish value.
diff --git a/docs/reference/index/variables/aggregationFn_max.md b/docs/reference/index/variables/aggregationFn_max.md
index c99ef8ec04..14ca7ac698 100644
--- a/docs/reference/index/variables/aggregationFn_max.md
+++ b/docs/reference/index/variables/aggregationFn_max.md
@@ -9,7 +9,7 @@ title: aggregationFn_max
 const aggregationFn_max: AggregationFnDef<any, any, unknown, RangeValue | undefined>;
 ```
 
-Defined in: [features/row-aggregation/aggregationFns.ts:109](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L109)
+Defined in: [features/row-aggregation/aggregationFns.ts:112](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L112)
 
 Finds the maximum numeric or Date value from the selected rows. Invalid value
 types are ignored; `NaN` preserves the legacy numeric seeding behavior.
diff --git a/docs/reference/index/variables/aggregationFn_mean.md b/docs/reference/index/variables/aggregationFn_mean.md
index a64c335ce3..0db4de0060 100644
--- a/docs/reference/index/variables/aggregationFn_mean.md
+++ b/docs/reference/index/variables/aggregationFn_mean.md
@@ -9,7 +9,7 @@ title: aggregationFn_mean
 const aggregationFn_mean: AggregationFnDef<any, any, unknown, number | undefined>;
 ```
 
-Defined in: [features/row-aggregation/aggregationFns.ts:201](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L201)
+Defined in: [features/row-aggregation/aggregationFns.ts:235](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L235)
 
 Averages number and number-like row values. Nullish and non-numeric values
 are ignored; other values retain the legacy unary-plus coercion behavior.
diff --git a/docs/reference/index/variables/aggregationFn_median.md b/docs/reference/index/variables/aggregationFn_median.md
index b0b1efe1bd..029675e0d4 100644
--- a/docs/reference/index/variables/aggregationFn_median.md
+++ b/docs/reference/index/variables/aggregationFn_median.md
@@ -9,7 +9,7 @@ title: aggregationFn_median
 const aggregationFn_median: AggregationFnDef<any, any, unknown, number | undefined>;
 ```
 
-Defined in: [features/row-aggregation/aggregationFns.ts:227](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L227)
+Defined in: [features/row-aggregation/aggregationFns.ts:262](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L262)
 
 Computes the median when every row value is a number. Returns `undefined`
 for empty inputs or when any value is non-numeric.
diff --git a/docs/reference/index/variables/aggregationFn_min.md b/docs/reference/index/variables/aggregationFn_min.md
index ec661b7605..cfde98f631 100644
--- a/docs/reference/index/variables/aggregationFn_min.md
+++ b/docs/reference/index/variables/aggregationFn_min.md
@@ -9,7 +9,7 @@ title: aggregationFn_min
 const aggregationFn_min: AggregationFnDef<any, any, unknown, RangeValue | undefined>;
 ```
 
-Defined in: [features/row-aggregation/aggregationFns.ts:73](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L73)
+Defined in: [features/row-aggregation/aggregationFns.ts:63](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L63)
 
 Finds the minimum numeric or Date value from the selected rows. Invalid value
 types are ignored; `NaN` preserves the legacy numeric seeding behavior.
diff --git a/docs/reference/index/variables/aggregationFn_sum.md b/docs/reference/index/variables/aggregationFn_sum.md
index 8661685561..dd2f8b6083 100644
--- a/docs/reference/index/variables/aggregationFn_sum.md
+++ b/docs/reference/index/variables/aggregationFn_sum.md
@@ -9,7 +9,7 @@ title: aggregationFn_sum
 const aggregationFn_sum: AggregationFnDef<any, any, unknown, number>;
 ```
 
-Defined in: [features/row-aggregation/aggregationFns.ts:45](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L45)
+Defined in: [features/row-aggregation/aggregationFns.ts:34](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L34)
 
 Sums numeric selected-row values. Non-number values contribute zero. As in
 the previous API, `NaN` is a number and therefore propagates through the sum.
diff --git a/docs/reference/index/variables/aggregationFn_unique.md b/docs/reference/index/variables/aggregationFn_unique.md
index 99c015d042..8d839d4375 100644
--- a/docs/reference/index/variables/aggregationFn_unique.md
+++ b/docs/reference/index/variables/aggregationFn_unique.md
@@ -9,6 +9,6 @@ title: aggregationFn_unique
 const aggregationFn_unique: AggregationFnDef<any, any, unknown, unknown[]>;
 ```
 
-Defined in: [features/row-aggregation/aggregationFns.ts:250](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L250)
+Defined in: [features/row-aggregation/aggregationFns.ts:286](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L286)
 
 Collects distinct row values using JavaScript `Set` semantics.
diff --git a/docs/reference/index/variables/aggregationFn_uniqueCount.md b/docs/reference/index/variables/aggregationFn_uniqueCount.md
index 8a993463c4..ec2185e96a 100644
--- a/docs/reference/index/variables/aggregationFn_uniqueCount.md
+++ b/docs/reference/index/variables/aggregationFn_uniqueCount.md
@@ -9,6 +9,6 @@ title: aggregationFn_uniqueCount
 const aggregationFn_uniqueCount: AggregationFnDef<any, any, unknown, number>;
 ```
 
-Defined in: [features/row-aggregation/aggregationFns.ts:266](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L266)
+Defined in: [features/row-aggregation/aggregationFns.ts:303](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L303)
 
 Counts distinct row values using JavaScript `Set` semantics.
diff --git a/docs/reference/index/variables/aggregationFns.md b/docs/reference/index/variables/aggregationFns.md
index ed6ceee628..cc2bb426f8 100644
--- a/docs/reference/index/variables/aggregationFns.md
+++ b/docs/reference/index/variables/aggregationFns.md
@@ -9,7 +9,7 @@ title: aggregationFns
 const aggregationFns: object;
 ```
 
-Defined in: [features/row-aggregation/aggregationFns.ts:331](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L331)
+Defined in: [features/row-aggregation/aggregationFns.ts:369](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/aggregationFns.ts#L369)
 
 Full built-in registry. Register individual definitions for tree-shaking.
 
diff --git a/docs/reference/static-functions/functions/aggregateColumnValue.md b/docs/reference/static-functions/functions/aggregateColumnValue.md
index 53b17407e4..37f7a9d85b 100644
--- a/docs/reference/static-functions/functions/aggregateColumnValue.md
+++ b/docs/reference/static-functions/functions/aggregateColumnValue.md
@@ -9,7 +9,7 @@ title: aggregateColumnValue
 function aggregateColumnValue<TFeatures, TData>(args): unknown;
 ```
 
-Defined in: [features/row-aggregation/rowAggregationFeature.utils.ts:261](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/rowAggregationFeature.utils.ts#L261)
+Defined in: [features/row-aggregation/rowAggregationFeature.utils.ts:307](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/rowAggregationFeature.utils.ts#L307)
 
 Executes every configured aggregation over a depth-selected row frontier.
 
@@ -47,6 +47,14 @@ readonly [`Row`](../../index/type-aliases/Row.md)\<`TFeatures`, `TData`\>[]
 
 readonly [`Row`](../../index/type-aliases/Row.md)\<`TFeatures`, `TData`\>[]
 
+#### uniqueRows?
+
+`boolean`
+
+Marks `rows` as distinct nodes of a single row tree (rows the table's own
+row models produced), enabling frontier selection without the
+duplicate-id guard. Caller-supplied row arrays must omit this.
+
 ## Returns
 
 `unknown`
diff --git a/docs/reference/static-functions/functions/cell_getIsAggregated.md b/docs/reference/static-functions/functions/cell_getIsAggregated.md
index fe8c464dde..11f960b9cb 100644
--- a/docs/reference/static-functions/functions/cell_getIsAggregated.md
+++ b/docs/reference/static-functions/functions/cell_getIsAggregated.md
@@ -9,7 +9,7 @@ title: cell_getIsAggregated
 function cell_getIsAggregated<TFeatures, TData, TValue>(cell): boolean;
 ```
 
-Defined in: [features/row-aggregation/rowAggregationFeature.utils.ts:393](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/rowAggregationFeature.utils.ts#L393)
+Defined in: [features/row-aggregation/rowAggregationFeature.utils.ts:450](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/rowAggregationFeature.utils.ts#L450)
 
 Implements `cell.getIsAggregated()` for synthetic grouped rows.
 
diff --git a/docs/reference/static-functions/functions/column_getAggregationFns.md b/docs/reference/static-functions/functions/column_getAggregationFns.md
index 6e46a9e703..2974ca4a65 100644
--- a/docs/reference/static-functions/functions/column_getAggregationFns.md
+++ b/docs/reference/static-functions/functions/column_getAggregationFns.md
@@ -9,7 +9,7 @@ title: column_getAggregationFns
 function column_getAggregationFns<TFeatures, TData, TValue>(column): readonly ResolvedAggregationFn<TFeatures, TData>[];
 ```
 
-Defined in: [features/row-aggregation/rowAggregationFeature.utils.ts:155](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/rowAggregationFeature.utils.ts#L155)
+Defined in: [features/row-aggregation/rowAggregationFeature.utils.ts:201](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/rowAggregationFeature.utils.ts#L201)
 
 Resolves and validates a column's scalar or multiple aggregation option.
 
diff --git a/docs/reference/static-functions/functions/column_getAggregationValue.md b/docs/reference/static-functions/functions/column_getAggregationValue.md
index 17ef1824ad..1121ccef2f 100644
--- a/docs/reference/static-functions/functions/column_getAggregationValue.md
+++ b/docs/reference/static-functions/functions/column_getAggregationValue.md
@@ -9,7 +9,7 @@ title: column_getAggregationValue
 function column_getAggregationValue<TFeatures, TData, TValue>(column, options?): ColumnAggregationValue<TFeatures>;
 ```
 
-Defined in: [features/row-aggregation/rowAggregationFeature.utils.ts:330](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/rowAggregationFeature.utils.ts#L330)
+Defined in: [features/row-aggregation/rowAggregationFeature.utils.ts:386](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/rowAggregationFeature.utils.ts#L386)
 
 Implements `column.getAggregationValue(options?)` and its default cache.
 
diff --git a/docs/reference/static-functions/functions/column_getAutoAggregationFn.md b/docs/reference/static-functions/functions/column_getAutoAggregationFn.md
index 3f8ecf3189..ffd34f4af4 100644
--- a/docs/reference/static-functions/functions/column_getAutoAggregationFn.md
+++ b/docs/reference/static-functions/functions/column_getAutoAggregationFn.md
@@ -11,7 +11,7 @@ function column_getAutoAggregationFn<TFeatures, TData, TValue>(column):
   | undefined;
 ```
 
-Defined in: [features/row-aggregation/rowAggregationFeature.utils.ts:113](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/rowAggregationFeature.utils.ts#L113)
+Defined in: [features/row-aggregation/rowAggregationFeature.utils.ts:159](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/rowAggregationFeature.utils.ts#L159)
 
 Resolves the `sum` or `extent` definition inferred from the first core row.
 
diff --git a/docs/reference/static-functions/functions/formatAggregatedCellValue.md b/docs/reference/static-functions/functions/formatAggregatedCellValue.md
index bdc2fea8f3..2cfa6f6b1d 100644
--- a/docs/reference/static-functions/functions/formatAggregatedCellValue.md
+++ b/docs/reference/static-functions/functions/formatAggregatedCellValue.md
@@ -9,7 +9,7 @@ title: formatAggregatedCellValue
 function formatAggregatedCellValue(value, option): string | null;
 ```
 
-Defined in: [features/row-aggregation/rowAggregationFeature.utils.ts:414](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/rowAggregationFeature.utils.ts#L414)
+Defined in: [features/row-aggregation/rowAggregationFeature.utils.ts:471](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/rowAggregationFeature.utils.ts#L471)
 
 Formats the default scalar or keyed aggregated-cell representation.
 
diff --git a/docs/reference/static-functions/functions/isRowSelected.md b/docs/reference/static-functions/functions/isRowSelected.md
index 8c02ea47e0..1139c47068 100644
--- a/docs/reference/static-functions/functions/isRowSelected.md
+++ b/docs/reference/static-functions/functions/isRowSelected.md
@@ -9,7 +9,7 @@ title: isRowSelected
 function isRowSelected<TFeatures, TData>(row, rowSelection): boolean;
 ```
 
-Defined in: [features/row-selection/rowSelectionFeature.utils.ts:868](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L868)
+Defined in: [features/row-selection/rowSelectionFeature.utils.ts:869](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L869)
 
 Returns whether a row id is selected in the current row selection state.
 
diff --git a/docs/reference/static-functions/functions/isSubRowSelected.md b/docs/reference/static-functions/functions/isSubRowSelected.md
index 91a6d0ec3e..7f76cf0efb 100644
--- a/docs/reference/static-functions/functions/isSubRowSelected.md
+++ b/docs/reference/static-functions/functions/isSubRowSelected.md
@@ -9,7 +9,7 @@ title: isSubRowSelected
 function isSubRowSelected<TFeatures, TData>(row): boolean | "some" | "all";
 ```
 
-Defined in: [features/row-selection/rowSelectionFeature.utils.ts:885](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L885)
+Defined in: [features/row-selection/rowSelectionFeature.utils.ts:886](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L886)
 
 Returns whether all, some, or none of a row's selectable descendants are selected.
 
diff --git a/docs/reference/static-functions/functions/normalizeUniqueAggregationRows.md b/docs/reference/static-functions/functions/normalizeUniqueAggregationRows.md
new file mode 100644
index 0000000000..572a573135
--- /dev/null
+++ b/docs/reference/static-functions/functions/normalizeUniqueAggregationRows.md
@@ -0,0 +1,42 @@
+---
+id: normalizeUniqueAggregationRows
+title: normalizeUniqueAggregationRows
+---
+
+# Function: normalizeUniqueAggregationRows()
+
+```ts
+function normalizeUniqueAggregationRows<TFeatures, TData>(rows, maxDepth): readonly Row<TFeatures, TData>[];
+```
+
+Defined in: [features/row-aggregation/rowAggregationFeature.utils.ts:105](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-aggregation/rowAggregationFeature.utils.ts#L105)
+
+Frontier selection for rows that are distinct nodes of a single row tree —
+the row models the table builds itself. Skips `normalizeAggregationRows`'
+duplicate-id guard (disjoint subtrees cannot revisit a row) and returns
+`rows` unchanged when no row descends, so the default `maxDepth: 0` case
+costs nothing per aggregation.
+
+## Type Parameters
+
+### TFeatures
+
+`TFeatures` *extends* [`TableFeatures`](../../index/interfaces/TableFeatures.md)
+
+### TData
+
+`TData` *extends* [`RowData`](../../index/type-aliases/RowData.md)
+
+## Parameters
+
+### rows
+
+readonly [`Row`](../../index/type-aliases/Row.md)\<`TFeatures`, `TData`\>[]
+
+### maxDepth
+
+`number` = `0`
+
+## Returns
+
+readonly [`Row`](../../index/type-aliases/Row.md)\<`TFeatures`, `TData`\>[]
diff --git a/docs/reference/static-functions/functions/row_getCanMultiSelect.md b/docs/reference/static-functions/functions/row_getCanMultiSelect.md
index 882c89ee0c..9a063c0da0 100644
--- a/docs/reference/static-functions/functions/row_getCanMultiSelect.md
+++ b/docs/reference/static-functions/functions/row_getCanMultiSelect.md
@@ -9,7 +9,7 @@ title: row_getCanMultiSelect
 function row_getCanMultiSelect<TFeatures, TData>(row): boolean;
 ```
 
-Defined in: [features/row-selection/rowSelectionFeature.utils.ts:633](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L633)
+Defined in: [features/row-selection/rowSelectionFeature.utils.ts:634](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L634)
 
 Checks whether this row can be selected alongside other rows.
 
diff --git a/docs/reference/static-functions/functions/row_getCanSelect.md b/docs/reference/static-functions/functions/row_getCanSelect.md
index 8fdedba827..569ab7a2c4 100644
--- a/docs/reference/static-functions/functions/row_getCanSelect.md
+++ b/docs/reference/static-functions/functions/row_getCanSelect.md
@@ -9,7 +9,7 @@ title: row_getCanSelect
 function row_getCanSelect<TFeatures, TData>(row): boolean;
 ```
 
-Defined in: [features/row-selection/rowSelectionFeature.utils.ts:587](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L587)
+Defined in: [features/row-selection/rowSelectionFeature.utils.ts:588](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L588)
 
 Checks whether this row can be selected.
 
diff --git a/docs/reference/static-functions/functions/row_getCanSelectSubRows.md b/docs/reference/static-functions/functions/row_getCanSelectSubRows.md
index f7f6c43b08..45a929e4f7 100644
--- a/docs/reference/static-functions/functions/row_getCanSelectSubRows.md
+++ b/docs/reference/static-functions/functions/row_getCanSelectSubRows.md
@@ -9,7 +9,7 @@ title: row_getCanSelectSubRows
 function row_getCanSelectSubRows<TFeatures, TData>(row): boolean;
 ```
 
-Defined in: [features/row-selection/rowSelectionFeature.utils.ts:610](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L610)
+Defined in: [features/row-selection/rowSelectionFeature.utils.ts:611](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L611)
 
 Checks whether selecting this row should also select its subRows.
 
diff --git a/docs/reference/static-functions/functions/row_getIsAllSubRowsSelected.md b/docs/reference/static-functions/functions/row_getIsAllSubRowsSelected.md
index f2ca7bb73e..99bbc94068 100644
--- a/docs/reference/static-functions/functions/row_getIsAllSubRowsSelected.md
+++ b/docs/reference/static-functions/functions/row_getIsAllSubRowsSelected.md
@@ -9,7 +9,7 @@ title: row_getIsAllSubRowsSelected
 function row_getIsAllSubRowsSelected<TFeatures, TData>(row): boolean;
 ```
 
-Defined in: [features/row-selection/rowSelectionFeature.utils.ts:569](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L569)
+Defined in: [features/row-selection/rowSelectionFeature.utils.ts:570](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L570)
 
 Checks whether all selectable descendants are selected.
 
diff --git a/docs/reference/static-functions/functions/row_getIsSelected.md b/docs/reference/static-functions/functions/row_getIsSelected.md
index 6fc16bc9fa..a829e0869c 100644
--- a/docs/reference/static-functions/functions/row_getIsSelected.md
+++ b/docs/reference/static-functions/functions/row_getIsSelected.md
@@ -9,7 +9,7 @@ title: row_getIsSelected
 function row_getIsSelected<TFeatures, TData>(row): boolean;
 ```
 
-Defined in: [features/row-selection/rowSelectionFeature.utils.ts:534](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L534)
+Defined in: [features/row-selection/rowSelectionFeature.utils.ts:535](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L535)
 
 Checks whether this row id is selected in `state.rowSelection`.
 
diff --git a/docs/reference/static-functions/functions/row_getIsSomeSelected.md b/docs/reference/static-functions/functions/row_getIsSomeSelected.md
index 7a55c6da32..fa1a80d408 100644
--- a/docs/reference/static-functions/functions/row_getIsSomeSelected.md
+++ b/docs/reference/static-functions/functions/row_getIsSomeSelected.md
@@ -9,7 +9,7 @@ title: row_getIsSomeSelected
 function row_getIsSomeSelected<TFeatures, TData>(row): boolean;
 ```
 
-Defined in: [features/row-selection/rowSelectionFeature.utils.ts:552](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L552)
+Defined in: [features/row-selection/rowSelectionFeature.utils.ts:553](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L553)
 
 Checks whether some, but not all, selectable descendants are selected.
 
diff --git a/docs/reference/static-functions/functions/row_getToggleSelectedHandler.md b/docs/reference/static-functions/functions/row_getToggleSelectedHandler.md
index 3edbafe674..083c118599 100644
--- a/docs/reference/static-functions/functions/row_getToggleSelectedHandler.md
+++ b/docs/reference/static-functions/functions/row_getToggleSelectedHandler.md
@@ -9,7 +9,7 @@ title: row_getToggleSelectedHandler
 function row_getToggleSelectedHandler<TFeatures, TData>(row, opts?): (e) => void;
 ```
 
-Defined in: [features/row-selection/rowSelectionFeature.utils.ts:660](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L660)
+Defined in: [features/row-selection/rowSelectionFeature.utils.ts:661](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L661)
 
 Creates a checkbox-style handler that selects or deselects this row.
 
diff --git a/docs/reference/static-functions/functions/row_toggleSelected.md b/docs/reference/static-functions/functions/row_toggleSelected.md
index a507b6d89f..b971b2c05d 100644
--- a/docs/reference/static-functions/functions/row_toggleSelected.md
+++ b/docs/reference/static-functions/functions/row_toggleSelected.md
@@ -12,12 +12,13 @@ function row_toggleSelected<TFeatures, TData>(
    opts?): void;
 ```
 
-Defined in: [features/row-selection/rowSelectionFeature.utils.ts:501](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L501)
+Defined in: [features/row-selection/rowSelectionFeature.utils.ts:502](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L502)
 
 Selects or deselects this row.
 
 Omitting `value` toggles the row. Child rows are selected recursively unless
-`opts.selectChildren` is `false` or sub-row selection is disabled.
+`opts.selectChildren` is `false`, sub-row selection is disabled, or the row
+only supports single selection.
 
 ## Type Parameters
 
diff --git a/docs/reference/static-functions/functions/selectRowsFn.md b/docs/reference/static-functions/functions/selectRowsFn.md
index 37f5847434..3985c846f5 100644
--- a/docs/reference/static-functions/functions/selectRowsFn.md
+++ b/docs/reference/static-functions/functions/selectRowsFn.md
@@ -9,7 +9,7 @@ title: selectRowsFn
 function selectRowsFn<TFeatures, TData>(rowModel, table): RowModel<TFeatures, TData>;
 ```
 
-Defined in: [features/row-selection/rowSelectionFeature.utils.ts:809](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L809)
+Defined in: [features/row-selection/rowSelectionFeature.utils.ts:810](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-selection/rowSelectionFeature.utils.ts#L810)
 
 Builds a row model containing rows selected by the current row selection state.
 
diff --git a/docs/reference/static-functions/index.md b/docs/reference/static-functions/index.md
index 834e880057..1f4da5647c 100644
--- a/docs/reference/static-functions/index.md
+++ b/docs/reference/static-functions/index.md
@@ -87,6 +87,7 @@ title: static-functions
 - [isSubRowSelected](functions/isSubRowSelected.md)
 - [isTouchStartEvent](functions/isTouchStartEvent.md)
 - [normalizeAggregationRows](functions/normalizeAggregationRows.md)
+- [normalizeUniqueAggregationRows](functions/normalizeUniqueAggregationRows.md)
 - [orderColumns](functions/orderColumns.md)
 - [passiveEventSupported](functions/passiveEventSupported.md)
 - [row\_getAllCells](functions/row_getAllCells.md)
diff --git a/packages/table-core/src/core/cells/constructCell.ts b/packages/table-core/src/core/cells/constructCell.ts
index 2d23506026..65c393c938 100644
--- a/packages/table-core/src/core/cells/constructCell.ts
+++ b/packages/table-core/src/core/cells/constructCell.ts
@@ -51,5 +51,11 @@ export function constructCell<
   cell.id = `${row.id}_${column.id}`
   cell.row = row
 
+  // Initialize instance-specific data for features that need it
+  const initFns = table._cellInstanceInitFns!
+  for (let i = 0; i < initFns.length; i++) {
+    initFns[i]!(cell as Cell<TFeatures, TData, TValue>)
+  }
+
   return cell as Cell<TFeatures, TData, TValue>
 }
diff --git a/packages/table-core/src/core/columns/constructColumn.ts b/packages/table-core/src/core/columns/constructColumn.ts
index 35815746da..e3eb5bfcb8 100644
--- a/packages/table-core/src/core/columns/constructColumn.ts
+++ b/packages/table-core/src/core/columns/constructColumn.ts
@@ -1,4 +1,3 @@
-import {} from '../../utils'
 import type { Table_Internal } from '../../types/Table'
 import type { CellData, RowData } from '../../types/type-utils'
 import type { TableFeatures } from '../../types/TableFeatures'
@@ -118,9 +117,9 @@ export function constructColumn<
   column.parent = parent
 
   // Initialize instance-specific data for features that need it
-  const features = Object.values(table._features)
-  for (let i = 0; i < features.length; i++) {
-    features[i]!.initColumnInstanceData?.(column)
+  const initFns = table._columnInstanceInitFns!
+  for (let i = 0; i < initFns.length; i++) {
+    initFns[i]!(column as Column<TFeatures, TData, TValue>)
   }
 
   return column as Column<TFeatures, TData, TValue>
diff --git a/packages/table-core/src/core/headers/buildHeaderGroups.ts b/packages/table-core/src/core/headers/buildHeaderGroups.ts
index 8958997902..ff3391913a 100644
--- a/packages/table-core/src/core/headers/buildHeaderGroups.ts
+++ b/packages/table-core/src/core/headers/buildHeaderGroups.ts
@@ -51,6 +51,8 @@ export function buildHeaderGroups<
 
   const headerGroups: Array<HeaderGroup<TFeatures, TData>> = []
 
+  const headerGroupInitFns = table._headerGroupInstanceInitFns!
+
   const constructHeaderGroup = (
     headersToGroup: Array<Header<TFeatures, TData, TValue>>,
     depth: number,
@@ -119,6 +121,11 @@ export function buildHeaderGroups<
       headerToGroup.headerGroup = headerGroup
     })
 
+    // Initialize instance-specific data for features that need it
+    for (let i = 0; i < headerGroupInitFns.length; i++) {
+      headerGroupInitFns[i]!(headerGroup)
+    }
+
     headerGroups.push(headerGroup)
 
     if (depth > 0) {
diff --git a/packages/table-core/src/core/headers/constructHeader.ts b/packages/table-core/src/core/headers/constructHeader.ts
index 7e52343dfd..6cb5b2b4b3 100644
--- a/packages/table-core/src/core/headers/constructHeader.ts
+++ b/packages/table-core/src/core/headers/constructHeader.ts
@@ -63,5 +63,11 @@ export function constructHeader<
   header.rowSpan = 0
   header.subHeaders = []
 
+  // Initialize instance-specific data for features that need it
+  const initFns = table._headerInstanceInitFns!
+  for (let i = 0; i < initFns.length; i++) {
+    initFns[i]!(header as Header<TFeatures, TData, TValue>)
+  }
+
   return header as Header<TFeatures, TData, TValue>
 }
diff --git a/packages/table-core/src/core/table/constructTable.ts b/packages/table-core/src/core/table/constructTable.ts
index 2d706c8234..64a29c75ec 100644
--- a/packages/table-core/src/core/table/constructTable.ts
+++ b/packages/table-core/src/core/table/constructTable.ts
@@ -68,16 +68,6 @@ export function constructTable<
 
   const featuresList: Array<TableFeature> = Object.values(table._features)
 
-  const rowInstanceInitFns: Array<
-    NonNullable<TableFeature['initRowInstanceData']>
-  > = []
-  for (const feature of featuresList) {
-    if (feature.initRowInstanceData) {
-      rowInstanceInitFns.push(feature.initRowInstanceData.bind(feature))
-    }
-  }
-  table._rowInstanceInitFns = rowInstanceInitFns
-
   const defaultOptions = featuresList.reduce((obj, feature) => {
     return Object.assign(obj, feature.getDefaultTableOptions?.(table))
   }, {}) as TableOptions<TFeatures, TData>
@@ -176,10 +166,51 @@ export function constructTable<
     ),
   )
 
+  // pre-compute the init functions to make the other constructors faster
+  const cellInstanceInitFns: Array<
+    NonNullable<TableFeature['initCellInstanceData']>
+  > = []
+  const columnInstanceInitFns: Array<
+    NonNullable<TableFeature['initColumnInstanceData']>
+  > = []
+  const headerGroupInstanceInitFns: Array<
+    NonNullable<TableFeature['initHeaderGroupInstanceData']>
+  > = []
+  const headerInstanceInitFns: Array<
+    NonNullable<TableFeature['initHeaderInstanceData']>
+  > = []
+  const rowInstanceInitFns: Array<
+    NonNullable<TableFeature['initRowInstanceData']>
+  > = []
+
   for (let i = 0; i < featuresList.length; i++) {
-    featuresList[i]!.initTableInstanceData?.(table)
+    const feature = featuresList[i]!
+    if (feature.initCellInstanceData) {
+      cellInstanceInitFns.push(feature.initCellInstanceData.bind(feature))
+    }
+    if (feature.initColumnInstanceData) {
+      columnInstanceInitFns.push(feature.initColumnInstanceData.bind(feature))
+    }
+    if (feature.initHeaderGroupInstanceData) {
+      headerGroupInstanceInitFns.push(
+        feature.initHeaderGroupInstanceData.bind(feature),
+      )
+    }
+    if (feature.initHeaderInstanceData) {
+      headerInstanceInitFns.push(feature.initHeaderInstanceData.bind(feature))
+    }
+    if (feature.initRowInstanceData) {
+      rowInstanceInitFns.push(feature.initRowInstanceData.bind(feature))
+    }
+    feature.initTableInstanceData?.(table)
   }
 
+  table._cellInstanceInitFns = cellInstanceInitFns
+  table._columnInstanceInitFns = columnInstanceInitFns
+  table._headerGroupInstanceInitFns = headerGroupInstanceInitFns
+  table._headerInstanceInitFns = headerInstanceInitFns
+  table._rowInstanceInitFns = rowInstanceInitFns
+
   if (
     process.env.NODE_ENV === 'development' &&
     (tableOptions.debugAll || tableOptions.debugTable)
diff --git a/packages/table-core/src/core/table/coreTablesFeature.types.ts b/packages/table-core/src/core/table/coreTablesFeature.types.ts
index 80afe099e7..7dfaf87e80 100644
--- a/packages/table-core/src/core/table/coreTablesFeature.types.ts
+++ b/packages/table-core/src/core/table/coreTablesFeature.types.ts
@@ -161,10 +161,22 @@ export interface Table_CoreProperties<
    * Table reactivity bindings for interacting with TanStack Store.
    */
   readonly _reactivity: TableReactivityBindings
+  /**
+   * Cache of the `initCellInstanceData` functions for features that define one.
+   */
+  _cellInstanceInitFns?: Array<
+    NonNullable<TableFeature['initCellInstanceData']>
+  >
   /**
    * Prototype cache for Cell objects - shared by all cells in this table
    */
   _cellPrototype?: object
+  /**
+   * Cache of the `initColumnInstanceData` functions for features that define one.
+   */
+  _columnInstanceInitFns?: Array<
+    NonNullable<TableFeature['initColumnInstanceData']>
+  >
   /**
    * Prototype cache for Column objects - shared by all columns in this table
    */
@@ -173,6 +185,18 @@ export interface Table_CoreProperties<
    * The features that are enabled for the table.
    */
   readonly _features: Partial<CoreFeatures> & TFeatures
+  /**
+   * Cache of the `initHeaderGroupInstanceData` functions for features that define one.
+   */
+  _headerGroupInstanceInitFns?: Array<
+    NonNullable<TableFeature['initHeaderGroupInstanceData']>
+  >
+  /**
+   * Cache of the `initHeaderInstanceData` functions for features that define one.
+   */
+  _headerInstanceInitFns?: Array<
+    NonNullable<TableFeature['initHeaderInstanceData']>
+  >
   /**
    * Prototype cache for Header objects - shared by all headers in this table
    */
diff --git a/packages/table-core/src/types/TableFeatures.ts b/packages/table-core/src/types/TableFeatures.ts
index 56b063d509..10fe36c252 100644
--- a/packages/table-core/src/types/TableFeatures.ts
+++ b/packages/table-core/src/types/TableFeatures.ts
@@ -1,7 +1,10 @@
 import type { CoreFeatures } from '../core/coreFeatures'
 import type { CellData, RowData, UnionToIntersection } from './type-utils'
+import type { Cell } from './Cell'
 import type { Column } from './Column'
 import type { ColumnDefBase_All } from './ColumnDef'
+import type { Header } from './Header'
+import type { HeaderGroup } from './HeaderGroup'
 import type { Row } from './Row'
 import type { Table_Internal } from './Table'
 import type { TableOptions_All } from './TableOptions'
@@ -310,8 +313,8 @@ export interface TableFeatures
  *
  * Feature objects are registered in the table's `features` option. They can
  * contribute default state/options, default column definitions, table APIs,
- * shared prototype APIs for rows/columns/headers/cells, and per-instance row
- * or column data.
+ * shared prototype APIs for rows/columns/headers/cells, and per-instance data
+ * for tables, columns, rows, headers, header groups, and cells.
  */
 export interface TableFeature {
   /**
@@ -434,6 +437,22 @@ export interface TableFeature {
   >(
     table: Table_Internal<TFeatures, TData>,
   ) => void
+  /**
+   * Initializes instance-specific data on each cell.
+   *
+   * This runs for every constructed cell after core cell fields such as `id`,
+   * `column`, and `row` have been assigned. Cells are constructed lazily on
+   * first access per row/column pair and cached, so this runs once per cell
+   * instance. Use this for per-cell mutable data, caches, or annotations.
+   * Shared methods should be assigned via `assignCellPrototype` instead.
+   */
+  initCellInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    cell: Cell<TFeatures, TData, TValue>,
+  ) => void
   /**
    * Initializes instance-specific data on each column.
    *
@@ -449,6 +468,39 @@ export interface TableFeature {
   >(
     column: Column<TFeatures, TData, TValue>,
   ) => void
+  /**
+   * Initializes instance-specific data on each header group.
+   *
+   * This runs for every constructed header group after `depth`, `id`, and the
+   * fully populated `headers` array have been assigned. Header groups have no
+   * shared prototype, so this is their only per-instance extension point.
+   * Header groups are reconstructed whenever they recompute (e.g. column
+   * visibility, order, or pinning changes), so this reruns on every rebuild.
+   */
+  initHeaderGroupInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+  >(
+    headerGroup: HeaderGroup<TFeatures, TData>,
+  ) => void
+  /**
+   * Initializes instance-specific data on each header.
+   *
+   * This runs for every constructed header after core header fields such as
+   * `id`, `column`, `depth`, `index`, and `isPlaceholder` have been assigned,
+   * but before `subHeaders` are populated and before `headerGroup` is linked.
+   * Headers are reconstructed on every header group rebuild, so this reruns
+   * on every rebuild. Use this for per-header mutable data, caches, or
+   * annotations. Shared methods should be assigned via `assignHeaderPrototype`
+   * instead.
+   */
+  initHeaderInstanceData?: <
+    TFeatures extends TableFeatures,
+    TData extends RowData,
+    TValue extends CellData = CellData,
+  >(
+    header: Header<TFeatures, TData, TValue>,
+  ) => void
   /**
    * Initializes instance-specific data on each row.
    *
diff --git a/packages/table-core/tests/unit/core/cells/constructCell.test.ts b/packages/table-core/tests/unit/core/cells/constructCell.test.ts
index a7cfefbe22..a83afc38a7 100644
--- a/packages/table-core/tests/unit/core/cells/constructCell.test.ts
+++ b/packages/table-core/tests/unit/core/cells/constructCell.test.ts
@@ -3,6 +3,7 @@ import { constructTable } from '../../../../src'
 import { constructCell } from '../../../../src/core/cells/constructCell'
 import { testFeatures } from '../../../fixtures/features'
 import type { ColumnDef } from '../../../../src/types/ColumnDef'
+import type { TableFeature } from '../../../../src/types/TableFeatures'
 
 interface Person {
   firstName: string
@@ -38,4 +39,47 @@ describe('constructCell', () => {
     expect(coreCell.column).toBe(column)
     expect(coreCell.row).toBe(row)
   })
+
+  it('should initialize instance-specific cell data once per cell', () => {
+    let initCount = 0
+    const annotationFeature: TableFeature = {
+      initCellInstanceData: (cell) => {
+        Object.defineProperty(cell, 'instanceAnnotation', {
+          value: `${cell.row.id}_${cell.column.id}`,
+          enumerable: true,
+          configurable: true,
+        })
+        initCount++
+      },
+    }
+    const featuresWithAnnotations = {
+      ...features,
+      annotationFeature,
+    }
+
+    const table = constructTable<typeof featuresWithAnnotations, Person>({
+      features: featuresWithAnnotations,
+      columns: columns as any,
+      data: [{ firstName: 'Tanner' }, { firstName: 'Kevin' }],
+    })
+
+    const rows = table.getRowModel().rows
+    const firstCells = rows.flatMap((row) => row.getAllCells())
+
+    expect(firstCells.length).toBe(2)
+    for (const cell of firstCells) {
+      expect(
+        Object.prototype.hasOwnProperty.call(cell, 'instanceAnnotation'),
+      ).toBe(true)
+      expect((cell as any).instanceAnnotation).toBe(
+        `${cell.row.id}_${cell.column.id}`,
+      )
+    }
+    expect(initCount).toBe(2)
+
+    // Cells are cached per row/column pair, so re-access constructs no new cells
+    const secondCells = rows.flatMap((row) => row.getAllCells())
+    expect(secondCells[0]).toBe(firstCells[0])
+    expect(initCount).toBe(2)
+  })
 })
diff --git a/packages/table-core/tests/unit/core/headers/constructHeader.test.ts b/packages/table-core/tests/unit/core/headers/constructHeader.test.ts
index 792d135cde..cd44c3220d 100644
--- a/packages/table-core/tests/unit/core/headers/constructHeader.test.ts
+++ b/packages/table-core/tests/unit/core/headers/constructHeader.test.ts
@@ -3,6 +3,7 @@ import { constructTable } from '../../../../src'
 import { constructHeader } from '../../../../src/core/headers/constructHeader'
 import { testFeatures } from '../../../fixtures/features'
 import type { ColumnDef } from '../../../../src/types/ColumnDef'
+import type { TableFeature } from '../../../../src/types/TableFeatures'
 
 interface Person {
   firstName: string
@@ -46,4 +47,119 @@ describe('constructHeader', () => {
 
     expect(header.id).toBe(column.id)
   })
+
+  it('should initialize instance-specific header data for every header', () => {
+    const initializedHeaders: Array<{
+      id: string
+      isPlaceholder: boolean
+      subHeadersLengthAtInit: number
+    }> = []
+    const annotationFeature: TableFeature = {
+      initHeaderInstanceData: (header) => {
+        Object.defineProperty(header, 'instanceAnnotation', {
+          value: header.id,
+          enumerable: true,
+          configurable: true,
+        })
+        initializedHeaders.push({
+          id: header.id,
+          isPlaceholder: header.isPlaceholder,
+          subHeadersLengthAtInit: header.subHeaders.length,
+        })
+      },
+    }
+    const featuresWithAnnotations = {
+      ...features,
+      annotationFeature,
+    }
+    const groupedColumns: Array<
+      ColumnDef<typeof featuresWithAnnotations, Person, any>
+    > = [
+      {
+        id: 'group',
+        header: 'Group',
+        columns: [{ id: 'child', accessorKey: 'firstName' }],
+      },
+      { id: 'solo', accessorKey: 'firstName' },
+    ]
+
+    const table = constructTable<typeof featuresWithAnnotations, Person>({
+      features: featuresWithAnnotations,
+      columns: groupedColumns,
+      data: [],
+    })
+
+    const allHeaders = table
+      .getHeaderGroups()
+      .flatMap((headerGroup) => headerGroup.headers)
+
+    expect(allHeaders.length).toBeGreaterThan(0)
+    for (const header of allHeaders) {
+      expect(
+        Object.prototype.hasOwnProperty.call(header, 'instanceAnnotation'),
+      ).toBe(true)
+      expect((header as any).instanceAnnotation).toBe(header.id)
+    }
+
+    // Placeholder headers run the hook too
+    expect(
+      initializedHeaders.some((initialized) => initialized.isPlaceholder),
+    ).toBe(true)
+    // The hook runs during construction, before subHeaders are populated
+    for (const initialized of initializedHeaders) {
+      expect(initialized.subHeadersLengthAtInit).toBe(0)
+    }
+  })
+
+  it('should initialize instance-specific header group data for every header group', () => {
+    const initializedGroups: Array<{
+      id: string
+      headersCount: number
+      backRefsLinked: boolean
+    }> = []
+    const annotationFeature: TableFeature = {
+      initHeaderGroupInstanceData: (headerGroup) => {
+        initializedGroups.push({
+          id: headerGroup.id,
+          headersCount: headerGroup.headers.length,
+          backRefsLinked: headerGroup.headers.every(
+            (header) => header.headerGroup === headerGroup,
+          ),
+        })
+      },
+    }
+    const featuresWithAnnotations = {
+      ...features,
+      annotationFeature,
+    }
+    const groupedColumns: Array<
+      ColumnDef<typeof featuresWithAnnotations, Person, any>
+    > = [
+      {
+        id: 'group',
+        header: 'Group',
+        columns: [{ id: 'child', accessorKey: 'firstName' }],
+      },
+    ]
+
+    const table = constructTable<typeof featuresWithAnnotations, Person>({
+      features: featuresWithAnnotations,
+      columns: groupedColumns,
+      data: [],
+    })
+
+    const headerGroups = table.getHeaderGroups()
+
+    // The hook runs once per group, after its headers are fully populated
+    expect(headerGroups.length).toBe(2)
+    expect(initializedGroups.length).toBe(headerGroups.length)
+    for (const initialized of initializedGroups) {
+      expect(initialized.headersCount).toBeGreaterThan(0)
+      expect(initialized.backRefsLinked).toBe(true)
+    }
+
+    // Memoized header groups do not rebuild, so the hook does not rerun
+    table.getHeaderGroups()
+    expect(initializedGroups.length).toBe(headerGroups.length)
+  })
 })
diff --git a/packages/table-core/tests/unit/core/table/constructTable.test.ts b/packages/table-core/tests/unit/core/table/constructTable.test.ts
index 80fff54313..adecafbfe1 100644
--- a/packages/table-core/tests/unit/core/table/constructTable.test.ts
+++ b/packages/table-core/tests/unit/core/table/constructTable.test.ts
@@ -105,6 +105,59 @@ describe('constructTable', () => {
     expect(table.apiWithoutInit).toBe(true)
   })
 
+  it('pre-computes per-instance init functions bound to their feature', () => {
+    const initialized = new Set<string>()
+    // Method shorthand so each hook reads `this` from the feature object,
+    // proving the cached init fns are bound to their feature
+    const bindingFeature = {
+      marker: 'bound-feature',
+      initCellInstanceData(this: any) {
+        initialized.add(`cell:${this.marker}`)
+      },
+      initColumnInstanceData(this: any) {
+        initialized.add(`column:${this.marker}`)
+      },
+      initHeaderGroupInstanceData(this: any) {
+        initialized.add(`headerGroup:${this.marker}`)
+      },
+      initHeaderInstanceData(this: any) {
+        initialized.add(`header:${this.marker}`)
+      },
+      initRowInstanceData(this: any) {
+        initialized.add(`row:${this.marker}`)
+      },
+    } as TableFeature
+    const features = {
+      ...testFeatures({}),
+      bindingFeature,
+    } as any
+
+    const table = constructTable({
+      features,
+      columns: [{ id: 'first-name', accessorKey: 'firstName' }],
+      data: [{ firstName: 'Tanner' }],
+    } as any) as any
+
+    expect(table._cellInstanceInitFns).toHaveLength(1)
+    expect(table._columnInstanceInitFns).toHaveLength(1)
+    expect(table._headerGroupInstanceInitFns).toHaveLength(1)
+    expect(table._headerInstanceInitFns).toHaveLength(1)
+    expect(table._rowInstanceInitFns).toHaveLength(1)
+
+    table.getHeaderGroups()
+    table.getRowModel().rows.forEach((row: any) => row.getAllCells())
+
+    expect(initialized).toEqual(
+      new Set([
+        'cell:bound-feature',
+        'column:bound-feature',
+        'headerGroup:bound-feature',
+        'header:bound-feature',
+        'row:bound-feature',
+      ]),
+    )
+  })
+
   it('resets feature-owned table data after internal atoms without rerunning initialization', () => {
     const init = vi.fn((table: any) => {
       table.transientValue = 'initialized'