You can check out the speedrunning guide in the guides section of this speedrun.com page, but for some quick information, I'm using rivatuna to control the games framerate in a particular way to allow for more jumps before leaving the ground

Playing on the latest release and if you do a double jump glitch (bind space to scroll wheel if u can't do that in ur mouse software ur allowed to use something like x-mouse button control) and double jump into the slide to try and find the sweet spot where the trigger clips out, when I found it it took a couple tries but u can get more of a feel for the position with enough trying. Double jump can be awkward if ur refresh rate > 75hz