From c988f940fb613370dac988baefe1c1c21bfc6d8e Mon Sep 17 00:00:00 2001
From: Josh Black <joshblack@github.com>
Date: Thu, 15 Oct 2026 15:42:00 -0500
Subject: [PATCH 1/5] perf(react-compiler): enable useSafeTimeout

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: e632d4e3-54d2-4423-9888-8e37b00494a3
---
 .changeset/react-compiler-safe-timeout.md  | 5 +++++
 packages/react/script/react-compiler.mjs   | 1 -
 packages/react/src/hooks/useSafeTimeout.ts | 4 ++--
 3 files changed, 7 insertions(+), 3 deletions(-)
 create mode 100644 .changeset/react-compiler-safe-timeout.md

diff --git a/.changeset/react-compiler-safe-timeout.md b/.changeset/react-compiler-safe-timeout.md
new file mode 100644
index 00000000000..f03fcec132b
--- /dev/null
+++ b/.changeset/react-compiler-safe-timeout.md
@@ -0,0 +1,5 @@
+---
+'@primer/react': minor
+---
+
+useSafeTimeout: Support automatic memoization with React Compiler.
diff --git a/packages/react/script/react-compiler.mjs b/packages/react/script/react-compiler.mjs
index dab247978a0..1999567b8a1 100644
--- a/packages/react/script/react-compiler.mjs
+++ b/packages/react/script/react-compiler.mjs
@@ -39,7 +39,6 @@ const unsupportedPatterns = [
   'src/hooks/useOnEscapePress.ts',
   'src/hooks/useOnOutsideClick.tsx',
   'src/hooks/useResizeObserver.ts',
-  'src/hooks/useSafeTimeout.ts',
   'src/internal/hooks/__tests__/useFocus.test.tsx',
   'src/internal/hooks/useDevOnlyEffect.ts',
   'src/utils/StressTest.tsx',
diff --git a/packages/react/src/hooks/useSafeTimeout.ts b/packages/react/src/hooks/useSafeTimeout.ts
index 2ee793c24d8..96922e6c813 100644
--- a/packages/react/src/hooks/useSafeTimeout.ts
+++ b/packages/react/src/hooks/useSafeTimeout.ts
@@ -26,9 +26,9 @@ export default function useSafeTimeout(): {safeSetTimeout: SetTimeout; safeClear
   }, [])
 
   useEffect(() => {
+    const timerSet = timers.current
     return () => {
-      // eslint-disable-next-line react-hooks/exhaustive-deps
-      for (const id of timers.current) {
+      for (const id of timerSet) {
         clearTimeout(id)
       }
     }

From adfb9be19345cf07ab645715fe0d8eb917c7bd04 Mon Sep 17 00:00:00 2001
From: Josh Black <joshblack@github.com>
Date: Thu, 15 Oct 2026 15:43:54 -0500
Subject: [PATCH 2/5] perf(react-compiler): enable token remove buttons

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>\nCopilot-Session: e632d4e3-54d2-4423-9888-8e37b00494a3
---
 .changeset/react-compiler-token-remove-button.md | 5 +++++
 packages/react/script/react-compiler.mjs         | 1 -
 packages/react/src/Token/_RemoveTokenButton.tsx  | 6 +++---
 3 files changed, 8 insertions(+), 4 deletions(-)
 create mode 100644 .changeset/react-compiler-token-remove-button.md

diff --git a/.changeset/react-compiler-token-remove-button.md b/.changeset/react-compiler-token-remove-button.md
new file mode 100644
index 00000000000..9e40058af25
--- /dev/null
+++ b/.changeset/react-compiler-token-remove-button.md
@@ -0,0 +1,5 @@
+---
+'@primer/react': minor
+---
+
+Token, IssueLabelToken: Improve rendering performance with React Compiler support.
diff --git a/packages/react/script/react-compiler.mjs b/packages/react/script/react-compiler.mjs
index 1999567b8a1..ba04a363905 100644
--- a/packages/react/script/react-compiler.mjs
+++ b/packages/react/script/react-compiler.mjs
@@ -25,7 +25,6 @@ const unsupportedPatterns = [
   'src/SelectPanel/SelectPanel.test.tsx',
   'src/SelectPanel/SelectPanel.tsx',
   'src/Skeleton/SkeletonBox.figma.tsx',
-  'src/Token/_RemoveTokenButton.tsx',
   'src/TreeView/TreeView.features.stories.tsx',
   'src/TreeView/TreeView.tsx',
   'src/deprecated/utils/create-slots.tsx',
diff --git a/packages/react/src/Token/_RemoveTokenButton.tsx b/packages/react/src/Token/_RemoveTokenButton.tsx
index 4ac007ca5cc..c02402d79b8 100644
--- a/packages/react/src/Token/_RemoveTokenButton.tsx
+++ b/packages/react/src/Token/_RemoveTokenButton.tsx
@@ -22,12 +22,14 @@ const RemoveTokenButton = ({
   borderOffset = 0,
   as: _as,
   children: _children,
+  ref,
   ...rest
 }: React.PropsWithChildren<RemoveTokenButtonProps & {as?: React.ElementType}>) => {
   if (isParentInteractive) {
     return (
       <span
         {...rest}
+        ref={ref as React.Ref<HTMLSpanElement>}
         tabIndex={-1}
         aria-label={ariaLabel}
         data-size={size}
@@ -43,7 +45,6 @@ const RemoveTokenButton = ({
 
   return (
     <button
-      // eslint-disable-next-line react-hooks/refs
       {...rest}
       aria-label={'Remove token'}
       data-size={size}
@@ -51,8 +52,7 @@ const RemoveTokenButton = ({
       style={{
         transform: `translate(${borderOffset}px, -${borderOffset}px)`,
       }}
-      // eslint-disable-next-line react-hooks/refs
-      ref={rest.ref as React.Ref<HTMLButtonElement>}
+      ref={ref as React.Ref<HTMLButtonElement>}
       type="button"
     >
       <XIcon size={size === 'small' || size === 'medium' ? 12 : 16} />

From f1b80c8e8b8fa6fdbad59355cdbf11286a45d03b Mon Sep 17 00:00:00 2001
From: Josh Black <joshblack@github.com>
Date: Thu, 15 Oct 2026 15:48:44 -0500
Subject: [PATCH 3/5] perf(react-compiler): enable UnderlinePanels

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: e632d4e3-54d2-4423-9888-8e37b00494a3
---
 .changeset/react-compiler-underline-panels.md      |  5 +++++
 packages/react/script/react-compiler.mjs           |  1 -
 .../UnderlinePanels/UnderlinePanels.tsx            | 14 ++++++++------
 3 files changed, 13 insertions(+), 7 deletions(-)
 create mode 100644 .changeset/react-compiler-underline-panels.md

diff --git a/.changeset/react-compiler-underline-panels.md b/.changeset/react-compiler-underline-panels.md
new file mode 100644
index 00000000000..1d3ccfcb569
--- /dev/null
+++ b/.changeset/react-compiler-underline-panels.md
@@ -0,0 +1,5 @@
+---
+'@primer/react': minor
+---
+
+UnderlinePanels: Improve rendering performance with React Compiler support.
diff --git a/packages/react/script/react-compiler.mjs b/packages/react/script/react-compiler.mjs
index ba04a363905..c797624c1a3 100644
--- a/packages/react/script/react-compiler.mjs
+++ b/packages/react/script/react-compiler.mjs
@@ -30,7 +30,6 @@ const unsupportedPatterns = [
   'src/deprecated/utils/create-slots.tsx',
   'src/experimental/SelectPanel2/SelectPanel.tsx',
   'src/experimental/UnderlinePanels/UnderlinePanels.test.tsx',
-  'src/experimental/UnderlinePanels/UnderlinePanels.tsx',
   'src/hooks/useAnchoredPosition.ts',
   'src/hooks/useControllableState.ts',
   'src/hooks/useFocusTrap.ts',
diff --git a/packages/react/src/experimental/UnderlinePanels/UnderlinePanels.tsx b/packages/react/src/experimental/UnderlinePanels/UnderlinePanels.tsx
index 605229ea25a..5e47bad0ce6 100644
--- a/packages/react/src/experimental/UnderlinePanels/UnderlinePanels.tsx
+++ b/packages/react/src/experimental/UnderlinePanels/UnderlinePanels.tsx
@@ -147,19 +147,21 @@ const UnderlinePanels: FCWithSlotMarker<UnderlinePanelsProps> = ({
 
   const [tabs, tabPanels, tabsHaveIcons, selectedFromProps, tabValues, panelValues] = useMemo(() => {
     // Derived in render (not an effect) to avoid an empty-tablist frame.
-    let tabIndex = 0
-    let panelIndex = 0
+    const indices = {
+      tab: 0,
+      panel: 0,
+    }
 
     const childrenWithProps = Children.map(children, child => {
       if (isValidElement<TabProps & WithValue>(child) && (child.type === Tab || isSlot(child, Tab))) {
-        const value = child.props.value ?? `${tabIndex}`
-        tabIndex++
+        const value = child.props.value ?? `${indices.tab}`
+        indices.tab++
         return cloneElement(child, {value})
       }
 
       if (isValidElement<PanelProps & WithValue>(child) && (child.type === Panel || isSlot(child, Panel))) {
-        const value = child.props.value ?? `${panelIndex}`
-        panelIndex++
+        const value = child.props.value ?? `${indices.panel}`
+        indices.panel++
         return cloneElement(child, {value})
       }
       return child

From 507324a2b975bc002c59f38e1bc5ffb0af221f2c Mon Sep 17 00:00:00 2001
From: Josh Black <joshblack@github.com>
Date: Thu, 15 Oct 2026 16:03:52 -0500
Subject: [PATCH 4/5] refactor(Token): remove unused explicit ref handling

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: e632d4e3-54d2-4423-9888-8e37b00494a3
---
 packages/react/src/Token/_RemoveTokenButton.tsx | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/packages/react/src/Token/_RemoveTokenButton.tsx b/packages/react/src/Token/_RemoveTokenButton.tsx
index c02402d79b8..9f1ed19ea2e 100644
--- a/packages/react/src/Token/_RemoveTokenButton.tsx
+++ b/packages/react/src/Token/_RemoveTokenButton.tsx
@@ -22,14 +22,12 @@ const RemoveTokenButton = ({
   borderOffset = 0,
   as: _as,
   children: _children,
-  ref,
   ...rest
 }: React.PropsWithChildren<RemoveTokenButtonProps & {as?: React.ElementType}>) => {
   if (isParentInteractive) {
     return (
       <span
         {...rest}
-        ref={ref as React.Ref<HTMLSpanElement>}
         tabIndex={-1}
         aria-label={ariaLabel}
         data-size={size}
@@ -52,7 +50,6 @@ const RemoveTokenButton = ({
       style={{
         transform: `translate(${borderOffset}px, -${borderOffset}px)`,
       }}
-      ref={ref as React.Ref<HTMLButtonElement>}
       type="button"
     >
       <XIcon size={size === 'small' || size === 'medium' ? 12 : 16} />

From 64fce7b1beacb0e1efe99f58b496aa9b8c28cac6 Mon Sep 17 00:00:00 2001
From: Josh Black <joshblack@github.com>
Date: Thu, 15 Oct 2026 16:22:37 -0500
Subject: [PATCH 5/5] fix(Token): exclude unsupported private remove-button
 refs

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: e632d4e3-54d2-4423-9888-8e37b00494a3
---
 packages/react/src/Token/_RemoveTokenButton.tsx | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/react/src/Token/_RemoveTokenButton.tsx b/packages/react/src/Token/_RemoveTokenButton.tsx
index 9f1ed19ea2e..84c5890a6fc 100644
--- a/packages/react/src/Token/_RemoveTokenButton.tsx
+++ b/packages/react/src/Token/_RemoveTokenButton.tsx
@@ -12,7 +12,8 @@ interface TokenButtonProps {
   isParentInteractive?: boolean
 }
 
-type RemoveTokenButtonProps = TokenButtonProps & Omit<React.HTMLProps<HTMLSpanElement | HTMLButtonElement>, 'size'>
+type RemoveTokenButtonProps = TokenButtonProps &
+  Omit<React.HTMLProps<HTMLSpanElement | HTMLButtonElement>, 'size' | 'ref'>
 
 const RemoveTokenButton = ({
   'aria-label': ariaLabel,