Just finished the default route so from what I've seen so far
A cosmetic change for the special lvl30 promotions, or at least change the animations, it's kinda disappointing having them just be the same with bigger numbers while the side characters get new weapons and skills, Nat automatic story reclass felt more the promotion than the actual promotion (looking forward to Lysandra new game plus upgrade though)
as an expansion of what the other guy said some limited reclassing options? maybe have them be support locked, ex. having all the chicken flashbacks and the junai/Lysandra support unlocks a chicken optional class change that lets her use canto (with an hypnosis scene of course) or someone to turn into a cow after Annie can't use the milk. mayyybe that's how we get Junai as an Animal in a turning the tables support (the ones I would wanna play as her are dog, gorilla and horse)
Adding game over quotes to the gallery and more short bad ends (could be a reward with those bonus requirements in maps without chests)
excited for corrupted hypnodom-Junai but wish there was more hypnosis with her cute regular self alongside just casual conversations after the midgame, and other characters speak with each other more
hoping none of these are super hard sorry if I underestimate some