the autosplitter does not work for later versions of the game. just the speedrun patch (1.1.6) alongside the pre-release (<-- for this one, i'm not too sure)

if I play at 23 fps but record video at 60 fps, will I need to calculate the final speedrun time at 60 fps?

yeah

how do you do the thing were mrdlex in alpha 3 no major skips wr he jumps through the hole in roof but have been trying that for ages and i cant do it

Crouch jump and then keep crouching in the air

do you have to keep going foward while in the air?

Yes

is there a way to fix it? (after I beat the game, I can't start a new one)

Idk try to open a level

Inject uuu in your game and type "open act1_main"

is there a command to open act 3 if so could i speedrun by using that on pre-release?

yes there is, use the command "open apartments"

thank you but do you know if it's allowed for the act speedruns

it is