so i was doing an all chapters glitched speedrun and got a new PB for chapter 1 is it possible for me to submit my all chapters glitched speedrun and then in a different submission cut the video before i begin chapter 2 for my new PB?

I'm pretty sure you can just submit the same video to both categories

so i can just submit the all chapters speedrun for the chapter 1 main route category and be fine even though it has the chapter 2 gameplay attached to it?

Yes that's fine

alr thanks :)