For 2.1, it would be good if Mods similar to Metal and Stars could add a second star map.
The exact details as to how the other star maps work would be up to interpretation but I do have some ideas, such as "Linked" space locations, perhaps to let players navigate between the starmaps they can ...

I do think that, the current system with the playlist is way to basic for much depth. So something that I would want in is the ability to link conditions to whether a song is on the playlist or not (as I have stated above). Otherwise I would prefer that music if scripted can be completely controlled ...

I have a lot of ideas for the Music engine, but this is a start. I do think a global stop would still be good, I have been thinking of making a jukebox mod that adds a jukebox and music discs and this would be a perfect use case. Further more, just because the base game does not have dynamic music ...