I think the issue with ffmpeg is that it needs to access GL driver libraries in order to support hardware acceleration. The GL libraries are dependent on your

I think the issue with ffmpeg is that it needs to access GL driver libraries in order to support hardware acceleration. The GL libraries are dependent on your hardware and have to match what you have installed on the system. So you'd end up having to support a hundred different variations of Firefox flatpacks and users would have to make sure they match when installing, and remember to uninstall and reinstall when they update their graphics drivers.