Matteo Caldari i personally would not expect it to do that. And I just tested the same in loopy pro, drambo and nanostudio 2 and they all stop playback (basically input & output) in background with that setting unchecked. But maybe i'm misunderstanding what you mean by active in background though.
Or put differently, this setting typically controls the ability of music apps to respond to midi etc in background to produce sound (in background). If sand does this even with the setting disabled, then I see no additional benefit of this toggle. Disabling this in other apps also helps preserve battery, which is what I usually disable it for. (if sand is active in background even without this enabled - does it mean it consumes battery all the time?)
True. I think this is actually the desired behaviour. I’d rather change the option description to “force active in background” and add an explanation that when playing the audio will stay active in any case.