Suggestion: Allow you to select your own battle music (or no battle music at all), even in Escha/Reisenjima.
We are already allowed to select our own title menu music. I think it seems like a bit of a shame we can't select our own Overworld/Dungeon battle music (I understand if they want boss battles to remain constant for thematic reasons however), especially since, as the game exists now, you don't really get to hear them unless you deliberately play a low level job to level in these places. Some of them are quite good too, like the RoZ overworld or WotG overworld. At the same time, I find not having a separate battle theme from time to time has its own merits. I would suggest a menu like:
Default
Base Game (Overworld)
Base Game (Dungeon)
Zilart (Overworld)
Zilart (Dungeon)
Promathia (Overworld)
Promathia (Dungeon)
Aht Urhgan (Overworld)
Aht Urhgan (Dungeon)
Goddess (Overworld)
Goddess (Dungeon)
Abyssea
Adoulin
No Music