I just got a top 600 time in but the run was rejected for using everest despite me launching the vanilla game off steam? What do I do, contact mods or what?

you cant use everest at speedruns, for disable just press right in the title screen, you cant do anything for you run be accept i think

If you have Everest installed, opening Celeste via Steam will open Celeste with Everest, not the vanilla game. You can either hold right on the title screen to reload into vanilla as ItzPriest mentioned, or another option is to download Olympus and use that as a launcher which includes an option to load directly into the vanilla game, amongst other features.

thanks guys, was so sad after submitting a 1:12:964 run

well thats frustrating