It seems like this is overriding the aether music, and mostly overworld music plays in the aether, with occasional aether music. Any idea why?

it does play biome specific music(the ather music) and general game music, while the biome music has a higher chance to occur. I would btw recommend to disable the aether's music manager in its client config

Oh ok gotcha. I tweaked some of the rules for allowing music to play under certain conditions as well, so I'll see if that helps. I'll try disabling the aether music manager as well. Thanks for the help!

added a new flag for other non minecraft dimension in the next version to use in the settings, that should be useful