Sitting on more JRPG ideas, and one that came to mind was:
What if a characters class gave them a multiplicative boost to their raw stats (1.2x, 1.5x, 0.9x, etc.)?
That way reclassing allows players to either round out a character's weakness, or to min-max their stats for optimal builds. A big factor of this system is that players can probably give any character any skill like in Final Fantasy, so this would be a way that they can all have unique roles instead of being "Sonic Tanks", where they go fast, soak damage, and hit like trains.