I have been using Safari on MacOS for a long time, but for various reasons decided to switch to Firefox now. The problem I have is that I can not find a way to open videos (e.g. YouTube) in full screen in a separate "space", so that I could use other tabs of firefox, while having a video in full screen. At first I couldn't even open Firefox in the native full screen on Mac, so it never opened in a separate space, but I fixed it in about:config by switching full-screen:macos-native-full-screen to true. Now when I go into full screen the entire browser goes into a separate space. Is it possible to keep Firefox on one space and open full screen video in another space?

I saw some discussion about it back from 2019, but no useful info there.