I'd would honestly love it if we could have your favorite playable animals appear in the main menu and in the quick match lobby just that alone would breathe in more life and personality with the menu and when you get together with your friends and see their favorite animals drop down onto the couch to game with you.
For quality of life i would absolutely love it if we could organize our character selection so we can easily switch between our favorite animals rather then having to go trough our entire collection just to go from Machigatto to Moonmon or Ori etc. With more and more characters being added into the game as playable, the amount of time spent switching characters will only increase...