I would love to see:
The other incarnates mentioned in mids
The return of Super Group base raids
A copy/paste option for base editing (of multiple items)
Mastermind pet customizations
A Tank class with crowd control might be interesting
A way to turn off the out dated graphics card check when opening the game
The ability to openly stream the game or post Youtube videos regularly like other games
An official mids designer that is updated as the game is updated
The release of the other pool powers listed in mids
Updated graphics engine would be really cool.
That's all I can think of at this moment. All of them are minor things, but might still be fun. I'll add more if I think of anything.