Hey yo I meant to reply a while ago but totally forgot to get to it. My bad! Here's the repo, it also has the Crown Tundra mons as well:
https://github.com/erlhuang/Dynamic-Pokemon-Expansion
I wouldn't be surprised if I forgot to commit the sprites for Gen 8; I can't be bothered to check it right now since my RR stuff is on a separate laptop that I haven't touched lately. If it's missing them let me know and I'll do an additional push.
Some things to note are the learnsets, basestats, eggmoves, and abilities.h are significantly altered so make sure you have the vanilla versions of those if you're trying to keep it vanilla in your hack. Cheers, let me know if you need anything!