diff --git a/packages/studio/src/hooks/gsapRuntimeReaders.test.ts b/packages/studio/src/hooks/gsapRuntimeReaders.test.ts
index b65f59237e..4e2f5485ea 100644
--- a/packages/studio/src/hooks/gsapRuntimeReaders.test.ts
+++ b/packages/studio/src/hooks/gsapRuntimeReaders.test.ts
@@ -1,5 +1,6 @@
 // @vitest-environment jsdom
 import { afterEach, describe, expect, it } from "vitest";
+import { gsap } from "gsap";
 import type { GsapAnimation } from "@hyperframes/core/gsap-parser";
 import {
   COLOR_GRADING_SOURCE_HIDDEN_ATTR,
@@ -109,3 +110,50 @@ describe("color-grading opacity truth", () => {
     expect(readGsapProperty(iframe, "#clip", "opacity")).toBe(0.3);
   });
 });
+
+describe("readAllAnimatedProperties with a sibling tween", () => {
+  it("leaves a sibling tween's rotation to that tween after an opacity keyframe edit", () => {
+    const el = document.createElement("div");
+    el.id = "clip";
+    document.body.appendChild(el);
+    const build = (keyframes: Record<string, Record<string, number>>) => {
+      const tl = gsap.timeline({ paused: true });
+      tl.to(el, { duration: 4, ease: "none", keyframes }, 0);
+      tl.to(el, { rotation: 90, duration: 3 }, 0);
+      return tl;
+    };
+    const live = build({ "0%": { opacity: 0 }, "100%": { opacity: 1 } });
+    live.seek(2);
+    const iframe = {
+      contentWindow: { __timelines: { main: live }, gsap },
+      contentDocument: document,
+    } as unknown as HTMLIFrameElement;
+    const anim = {
+      id: "#clip-to-0-visual",
+      targetSelector: "#clip",
+      method: "to",
+      properties: {},
+      keyframes: {
+        keyframes: [
+          { percentage: 0, properties: { opacity: 0 } },
+          { percentage: 100, properties: { opacity: 1 } },
+        ],
+      },
+    } as unknown as GsapAnimation;
+
+    // commitKeyframeProps: these values plus the edit at the playhead, and backfilled into the rest.
+    const read = readAllAnimatedProperties(iframe, "#clip", anim);
+    live.kill();
+    gsap.set(el, { clearProps: "all" });
+    const edited = build({
+      "0%": { ...read, opacity: 0 },
+      "50%": { ...read, opacity: 0.3 },
+      "100%": { ...read, opacity: 1 },
+    });
+    edited.seek(3.2);
+    edited.seek(3.5);
+
+    expect(gsap.getProperty(el, "rotation")).toBe(90);
+    edited.kill();
+  });
+});
diff --git a/packages/studio/src/hooks/gsapRuntimeReaders.ts b/packages/studio/src/hooks/gsapRuntimeReaders.ts
index 48d2ed3ffc..0bc7203ac4 100644
--- a/packages/studio/src/hooks/gsapRuntimeReaders.ts
+++ b/packages/studio/src/hooks/gsapRuntimeReaders.ts
@@ -8,6 +8,7 @@ import {
   HF_COLOR_GRADING_CANVAS_ID_PREFIX,
 } from "@hyperframes/core/color-grading";
 import { getIframeGsap, queryIframeElement, type IframeGsap } from "./gsapShared";
+import { gsapWritesChannels } from "./gsapRuntimeKeyframes";
 import { roundTo3 } from "../utils/rounding";
 
 /**
@@ -50,27 +51,6 @@ export function readGsapProperty(
 }
 
 export const POSITION_PROPS = new Set(["x", "y", "xPercent", "yPercent"]);
-const GSAP_CONFIG_KEYS = new Set([
-  "duration",
-  "ease",
-  "delay",
-  "stagger",
-  "id",
-  "onComplete",
-  "onUpdate",
-  "onStart",
-  "onRepeat",
-  "repeat",
-  "yoyo",
-  "repeatDelay",
-  "paused",
-  "immediateRender",
-  "lazy",
-  "overwrite",
-  "keyframes",
-  "parent",
-]);
-
 export function readAllAnimatedProperties(
   iframe: HTMLIFrameElement | null,
   selector: string,
@@ -115,74 +95,7 @@ export function readAllAnimatedProperties(
     }
   }
 
-  const otherTweenProps = new Set<string>();
-  try {
-    const win = iframe.contentWindow as unknown as { __timelines?: Record<string, unknown> };
-    const timelines = win.__timelines;
-    if (timelines) {
-      for (const tl of Object.values(timelines)) {
-        const tlObj = tl as {
-          getChildren?: (
-            deep: boolean,
-          ) => Array<{ targets?: () => Element[]; vars?: Record<string, unknown> }>;
-        };
-        if (!tlObj?.getChildren) continue;
-        for (const child of tlObj.getChildren(true)) {
-          if (typeof child.targets !== "function") continue;
-          const targets = child.targets();
-          if (!targets.includes(el)) continue;
-          const vars = child.vars;
-          if (!vars) continue;
-          for (const k of Object.keys(vars)) {
-            if (!GSAP_CONFIG_KEYS.has(k) && inGroup(k)) otherTweenProps.add(k);
-          }
-        }
-      }
-    }
-  } catch {}
-  for (const p of groupedPropKeys) otherTweenProps.delete(p);
-
-  // Tier 1: Transform + visual properties with universal CSS defaults.
-  // Safe to compare against hardcoded values — these are always 0 or 1
-  // regardless of the element's stylesheet.
-  const UNIVERSAL_BASELINE: Record<string, number> = {
-    opacity: 1,
-    scale: 1,
-    scaleX: 1,
-    scaleY: 1,
-    scaleZ: 1,
-    rotation: 0,
-    rotationX: 0,
-    rotationY: 0,
-    skewX: 0,
-    skewY: 0,
-    z: 0,
-    xPercent: 0,
-    yPercent: 0,
-    transformPerspective: 0,
-    blur: 0,
-    brightness: 1,
-    contrast: 1,
-    saturate: 1,
-    hueRotate: 0,
-    grayscale: 0,
-    sepia: 0,
-    invert: 0,
-  };
-  // Collect all properties that ANY tween on this element explicitly targets.
-  // Only capture baseline values for these — GSAP reports non-default values
-  // (scaleZ=0, brightness=0) for untouched properties, polluting keyframes.
-  const allTweenedProps = new Set([...groupedPropKeys, ...otherTweenProps]);
-  for (const [prop, defaultVal] of Object.entries(UNIVERSAL_BASELINE)) {
-    if (prop in result) continue;
-    if (!allTweenedProps.has(prop)) continue;
-    const val = readLiveGsapValue(gsap, el, prop);
-    if (Number.isFinite(val) && Math.round(val * 1000) !== Math.round(defaultVal * 1000)) {
-      result[prop] = roundTo3(val);
-    }
-  }
-
-  // Tier 2: Element-dependent properties — their "default" depends on the
+  // Element-dependent properties — their "default" depends on the
   // stylesheet, so we compare GSAP's runtime value against the element's
   // computed CSS value. Only capture if GSAP has actively changed it.
   const COMPUTED_BASELINE = [
@@ -209,7 +122,7 @@ export function readAllAnimatedProperties(
   for (const prop of COMPUTED_BASELINE) {
     if (prop in result) continue;
     if (!inGroup(prop)) continue;
-    if (otherTweenProps.has(prop)) continue;
+    if (gsapWritesChannels(el, [prop])) continue;
     const gsapVal = Number(gsap.getProperty(el, prop));
     if (!Number.isFinite(gsapVal)) continue;
     let cssVal = NaN;