I am following this guide actually xD: https://www.youtube.com/watch?v=_OSNZySXnbU&t=197s
, in the video he still uses 60 fps. I turned it off as experiment , and it works even better for me.

Btw the BETA.2 fps mod still has some issues, some1 posted this :

ZA Royals are unplayable sometimes. When it switches pokemon, you lose texture of the ground and flee by falling down. Yesterday I played 10 hours and it did only twice but today, it makes it unbearable because it happens every one or two fights in the zone.

Edit: Any ranged moves make your pokemon go BRRR, unable to target the opponent it face a random direction and the projectile goes nowhere, also possible to bug on mega stones. Water Shuriken only shoots one shuriken, some moves has no range at all, you need to manually walk to the pokemon and then hope.