How to record a video of a Jetpack Compose @Composable function without blocking UI thread?

Question

Context

I have a Jetpack Compose @Composable function that has a AndroidView (Camera previewview) and a Canvas that I draw on.

Here's a very simplified version of my code:

@Composable
fun ExerciseCanvasView(...) {
  Box(modifier = Modifier.fillMaxSize()) {
    AndroidView(...)
    Canvas(...)
  }
}

Basically, I want to record a video of this function and save it into a file (video.mp4).

What I've Tried:

• MediaProjection. I tried MediaProjection but is not what I want. It records the whole screen and I dont really need that and it might record sensitive info.
• Drawing a composeview to a canvas to a bitmap. I have tried this also, but the drawing has to be done in the Main UI Thread (this question) and this blocks the Main UI Thread, rendering it unusable.
• Some other deprecated shenanigans that chatgpt recommended that dont work at all.

For now, I dont care if even i have to save captures of the Composable and then encode them to a video or anything, I cant even make that to work...

Question

Has anyone faced a similar issue and found a solution to record only this specific @Composable without blocking the UI thread?