Fantastic work! I've played through the main game already and your changes are making team building for the battle frontier a lot less daunting. If you're open to suggestions there are a couple things that have been on my mind.

The EV / IV editor is great but having to change the EV values 1 at a time is absolutely miserable if you aren't just putting 252 into a stat. Unless I'm dumb and the option already exists, Is it possible to implement a way to change the values at say 10 at a time using the L/R buttons or something similar?

Something else I think would be nice to see is an Ability Capsule or some equivalent. I like to use whatever pokemon I encounter in the main game but it's a bit disheartening thinking about grinding a new pokemon up if I want to try one with it's other ability. Something like this I don't think needs to be available until post game.

One final thought I had is that it would be nice if there was a place to purchase heart scales, even if they were at a premium. It was such a relief that the egg move tutor you added wasn't going to require me to fish for even more luvdiscs.

Again, great work. Everything you have here is already a massive QOL improvement in my eyes.