The thing is this game use a lot of multiple channel especially the Satan Battle which has 3 at once. I don't know if someone is going to make every possible mix for this game...but that would a lot i mean doing every mix with channel 1 & 2 would required at least 316 tracks.
The game doesn't use every possible mix. For battles, it's either the first 2 channels (normal battle theme), or the last 2 channels (menu theme during battle). Satan/Dark Lord battle is 6 channels for transitioning between 3 songs that have 2 channels each. So I ripped them as they were intended to sound. Not sure what the point of doing random channel mixes would be, aside from experiments/personal preference.
The stage themes actually do use all 4 channels at once, but leaving them as 4-channel leaves them sounding too quiet (unless you have the right setup?). I have standard stereo speakers and average-quality earbuds for my computer, so that's pretty much what I tailored this rip for.
The .bcstm files I made the majority of this rip from (found in this forum's request section) only had one of the title themes, so I had to line-in the rest from my 3DS. I was worried about the quality on those, because I couldn't rip them properly in stereo, and just copied the left channel to the right. Only the "Otherworld" title is in stereo, because it was the only title theme in .bcstm form. I'm guessing it's because, unlike the Mii voices that sing randomly over the other titles, the vocals on Otherworld are always the same. So the other title themes must be stored differently in the game data.
By the way, just to be clear, here's what I mean when I talk about 4 or 6 channels:

BGM_BATTLE_WORLD1.bcstm (Battle: Greenhorne) made 2 separate files.

BGM_BATTLE_BOSS_SATAN.bcstm (Boss: The Dark Lord/Boss: The Dark Lord (Menu)/Boss: The Dark Lord's Wrath) made 3 separate files.
This is the first time I've had to make a rip with 4 or more channels that basically layered multiple tracks into the same file, and the first time I've had to use line-in just to match the in-game music list.
I'm hoping there's a way to rip ALL the music as .bcstm, or that someone else just rips the title themes in stereo, lol. I think I've done all I can here.