More Trainers to rechallenge as well as gym leaders

Theres only like... 10 trainers that I can rechallenge to battle against training my pokemon, I would like more trainers on all the routes and again able to rechallenge gym leaders (with heightened pokemon obviously)

Supposedly the Gym Leaders will be some of the trainers one fights at the Championship in addition to other key characters. That said, more rematch trainers in the east might be good.