I would love to have a decent AI for the autoplay mode for my team, at least at the level of the enemy's AI (like, heal when health is low, use shields when they are not up, etc). Another (related) idea could be to have a way to give basic instructions for the autoplay (like, this character only uses basic moves, this character can use power moves whenever he can, etc..).
(I really hate it when my red war dog in autoplay uses its stupid stun-bite instead of hitting AOE and healing itself in the process)
The way it is now I'm stuck auto-grinding levels that are way lower than what I can grind if I actually play them (which takes a lot of time), or I have to auto-grind higher levels and accept that I'll get a defeat sometimes.
Since the game requires a LOT of grinding to advance characters (and talismans) after a certain point, I personally am getting kind of frustrated with it, and I think this would somehow make it better.