I was speedrunning reach closest border when i came across this no idea how i did this but my w key got stuck when i entered the menu and then i had to press escape before i could use my mouse.

that happens all the time, there's an error with mouse capturing. I just hit escape before I start so I can press the start button

ok thanks, i know how to do it now anyway you just need to hold w and click somewhere during world gen you are then able to move the camera before you press start after you press start though it does count as the first input, you can see from the autosplitter it just means that you can start facing the ground for: reach bedrock break dirt or any other ore getting a view of you surroundings for any other runs

i think its quite useful not sure if its allowed though

I don't think that's allowed. We retime runs and, according the rules, time starts on first input (player or camera movement), whether or not it is before or after start is pressed.