A month and a day is hardly a bump, right?
Either way I've been interested in this too and at the very least seems to have an idea.
*snip*
The free spotpass DLC can be easily installed using the method in the link above. I tried copying and renaming some of Helena's files for kicks and I got the "a new costume has been added for Helena!" message a third time which implies the game recognized it as separate DLC. The third costume didn't get it's own slot, but I think that's because I used an unedited version of Helena's 2nd .bacs file. Since the files show little variance in a hex editor I figure someone smarter than me could probably figure out how to edit them to so the game interprets them as new slots. If so then adding DLC costumes would be just as simple as it is with Dissidia 12 on the PSP.
It's also worth noting Every File Explorer gives an error when trying to load a costume's bcmdl file.
"Can not activate GL rendering context."
I figure this might be an easy fix so I'm not going to worry much about it. My main concern is with that custom spotpass DLC.
In the meantime I'll be looking into what I can port from Dead or Alive: Paradise.