And i am pretty sure that there are users which want it blanked all the time because they use an old macbook dedicated as htpc and want the display to be blanked. This is hard to get right for everyone. Minimizing Kodi is something i would call acceptable from a user POV for your music use case. (iirc there is a shortcut for this?).
So we have 2 major use cases covered atm.
1. Old macbook used as dedicated HTPC attached to a TV - blanking turned on
2. Macbook not dedicated as HTPC connected to a second screen (or any other mac connected to more then 1 screen) - having kodi on one screen and keep working on the other (blanking turned off - aka "the usual kodi developer setup"
).
We don't have a generic solution for the intermediate use cases which want both at the same time (constraints differ from task to task - at some point int might be good to have it blanked only during playback - at others it might be the right thing to have it vice versa) and i think it would need some more settings.
More settings is something which we want to prevent for making Kodi not even more complex at least if we feel its not a killer feature that a lot of users benefit.
I became careful over the time with those sort of "easy" requests. They are easy. I did those similar changes and it sometimes just came back to me because after adding something like that other users spoke up that something they did before works different now. (and thats where it gets annoying for me because i didn't even care about the change in the first place and don't want to spend even more time on cleaning up the rats tail it results in).