The setting should appear from using the drunk world seed, because that was how you access it now.I think the soundtrack for otherworld should be in the audio settings rather than being something tied to the world. I love the soundtrack, but I dont like that I have to wait until much later in the game just so I can temporarily change the music.
I didnt plan on making it available without entering the drunk seed. It would appear as a sort of 'check box' once you enter the world seedThe setting should appear from using the drunk world seed, because that was how you access it now.