Thank you! You are absolutely right; the start/stop is not working perfectly at the moment. ‘Stop’ ends the music after it finishes the progression, ‘start’ immediately starts a new progression without waiting for the old to actually stop. Guess it’s worth to point out that this in no way is considered a finished product :)

Stop appears to cause the old instance to play through to the end, but not start a new instance right away. So it works, but it's really delayed; I think most users would expect an instant mute from a button labeled "Stop." Perhaps a relabel would set better expectations.

Interesting, I didn't test it that far. My pathetically low tolerance as a user kicked in beforehand. If it behaves more like "queue next", then that's what it should be named. Although, a queue next function without the concept of a playlist makes little sense compared to a stop/start.