Differentiate Spotpas from DLC from Streetpass characters is possible. That's how I achieved giving correct Portrait images to them. Although, it depends if the character has been hex edited, which could cause wrong info. But if taken directly from the game without any editing out of the editor, sure, they are fully identifiable.Would you be able to add a feature where you can view and possibly edit the Asset and Flaw of the Avatar? Also, are you able to differentiate "Outrealm Order" Avatars from normal StreetPass Avatars?
It's possible to edit the Asset and Flaw, however, I haven't looked into them that much, and haven't tested how it behaves once loaded in-game. I'll try to do something for the next update.