HERE IT IS! I know many of you wonderful people were asking for a part 2! I feel like this one is not as good as part 1 though ^^ I need some trigger ideas for the next one please!
To listen while using other apps, switch the player to Picture-in-Picture (PiP) during playback — it keeps playing in a small floating window (the screen stays on).
To listen with the screen fully off, in-browser playback stops by YouTube's design. Open the video in the YouTube app to keep listening where background playback is supported (e.g. with YouTube Premium).
Open in YouTube app