diff --git a/packages/studio/src/components/editor/manualEditsDomPatches.ts b/packages/studio/src/components/editor/manualEditsDomPatches.ts
index 1cfbf3e0a8..294b8406cc 100644
--- a/packages/studio/src/components/editor/manualEditsDomPatches.ts
+++ b/packages/studio/src/components/editor/manualEditsDomPatches.ts
@@ -118,7 +118,7 @@ export function buildClearPathOffsetPatches(element: HTMLElement): PatchOperatio
 
 /* ── Box size patches ────────────────────────────────────────────── */
 
-const BOX_SIZE_STYLE_PROPS = [
+export const BOX_SIZE_STYLE_PROPS = [
   "width",
   "height",
   "min-width",
diff --git a/packages/studio/src/components/editor/manualOffsetDrag.test.ts b/packages/studio/src/components/editor/manualOffsetDrag.test.ts
index 578229354e..21150fc3d4 100644
--- a/packages/studio/src/components/editor/manualOffsetDrag.test.ts
+++ b/packages/studio/src/components/editor/manualOffsetDrag.test.ts
@@ -686,7 +686,10 @@ describe("a resize's anchor member", () => {
     expect(member.element.style.getPropertyValue("translate")).toBe("-10.25px 3.5px");
   });
 
-  it("leaves a box whose size GSAP tweens to the GSAP writer", () => {
-    expect(anchorMember({ width: 300 }).plainTranslate).toBe(false);
-  });
+  it.each(["width", "maxWidth", "minHeight", "flexBasis", "scale"])(
+    "leaves a box whose %s GSAP tweens, which the CSS box writer also sets, to the GSAP writer",
+    (channel) => {
+      expect(anchorMember({ [channel]: 300 }).plainTranslate).toBe(false);
+    },
+  );
 });
diff --git a/packages/studio/src/hooks/gsapRuntimeKeyframes.ts b/packages/studio/src/hooks/gsapRuntimeKeyframes.ts
index fff34b57d2..bc9878e70d 100644
--- a/packages/studio/src/hooks/gsapRuntimeKeyframes.ts
+++ b/packages/studio/src/hooks/gsapRuntimeKeyframes.ts
@@ -11,6 +11,7 @@
 import { buildArcPath, type ArcPathConfig } from "@hyperframes/core/gsap-parser-acorn";
 import { parsePercentageKeyframes, toAbsoluteTime } from "./gsapShared";
 import { roundTo3 } from "../utils/rounding";
+import { BOX_SIZE_STYLE_PROPS } from "../components/editor/manualEditsDomPatches";
 
 /**
  * A GSAP tween's `vars` object — intentionally open: it mixes channel values
@@ -446,9 +447,13 @@ export function gsapWritesPosition(el: Element): boolean {
   return !!cache?.renderTransform || gsapWritesChannels(el, MOVE_CHANNELS);
 }
 
-/** GSAP owns this element's box: its position, or its width or height. Else a resize writes CSS. */
+const BOX_CHANNELS = BOX_SIZE_STYLE_PROPS.map((prop) =>
+  prop.replace(/-([a-z])/g, (_, c: string) => c.toUpperCase()),
+);
+
+/** GSAP owns this element's box: its position, or any property the CSS box writer sets. Else a resize writes CSS. */
 export function gsapWritesBox(el: Element): boolean {
-  return gsapWritesPosition(el) || gsapWritesChannels(el, ["width", "height"]);
+  return gsapWritesPosition(el) || gsapWritesChannels(el, BOX_CHANNELS);
 }
 
 /** `hasNonHoldTweenForElement` for an element in hand, read from its own window's timelines. */
diff --git a/packages/studio/src/hooks/useDomGeometryCommit.test.tsx b/packages/studio/src/hooks/useDomGeometryCommit.test.tsx
index 4a7c3814b0..2469187526 100644
--- a/packages/studio/src/hooks/useDomGeometryCommit.test.tsx
+++ b/packages/studio/src/hooks/useDomGeometryCommit.test.tsx
@@ -176,6 +176,28 @@ describe("useDomGeometryCommit, from the package entry", () => {
     unmount();
   });
 
+  it("saves a GSAP-free resize as its inline size, with no GSAP script and no animation read", async () => {
+    const calls = stubPatchServer();
+    const { element, recordEdit, hook, unmount } = renderHost();
+
+    await expect(
+      hook().commitBoxSize(makeSelection("card", element), { width: 300, height: 90 }),
+    ).resolves.toEqual({ ok: true });
+
+    expect(element.style.getPropertyValue("width")).toBe("300px");
+    expect(calls.patches).toEqual([
+      expect.objectContaining({
+        operations: expect.arrayContaining([
+          { type: "inline-style", property: "width", value: "300px" },
+          { type: "inline-style", property: "height", value: "90px" },
+        ]),
+      }),
+    ]);
+    expect(calls.urls.filter((url) => url.includes("gsap"))).toEqual([]);
+    expect(recordEdit).toHaveBeenCalledTimes(1);
+    unmount();
+  });
+
   it("puts a GSAP-free element's translate back when its move cannot be saved", async () => {
     stubPatchServer(500);
     const { element, hook, unmount } = renderHost();