Once long ago suggested by Satsune: Implement out-of-combat, relaxed music similar to Phantasy Star Online's feature. If it's not too much trouble, this could be pretty neat to re-have.
Suggestion by me: Could we actually get more new and unheard songs rather than always re-using old stuff even when we get a 'new' map? Unique areas deserve unique compositions, know? AoI only delivered us.. what - 4 new songs? (excluding boss themes and casino) Oh, and by old, this is not referring to when at events or party missions we get PSO or Sonic themes.. hey, THOSE are great! There's at least 4 places with the same old HIVE theme for example.. HIVE music in a HIVE, I know but.. HIVEs can be unique too.
I personally could ignore the fact that an area is just a re-skin if the music would be unique compared to the rest. I hope it's safe to say that "we" like your Phantasy Star-online series music compositions! Bring us more?