Is there/will there be, a templating type of feature? One thing that's bit me in the past is working Set A of cards, then working on Set B (different back, different card font) and then thinking Set A could benefit from the look of Set B and going back and changing all of A to match B. Then of course you start Set C and realize "Well, if this is going to be a Total Conversion type of Homebrew, then I really don't need to try to match the OG HQ Style, so I'm going to use my own font, neon colors, etc..." but now I have to go back to Set A and B and make all these changes.
It would be nice to be able to have the Text and Images as a separate thing, and apply those on top of various templates.
This would be a HUGE thing for me. Hopefully you are already doing this and we're just calling it different things, but if not, I'd be happy to help bring that feature into your app!