I recently watched 1-s speedruns and starting from the 4th place in the top, speedrunners use the skip through the first door. That is, they solve the first 3 initial puzzles and then exit to oob through the first door. How to do the same? Can anyone make a guide?

yeah, but for me with whiplash is much easier

The trigger skip can be done not everywhere, but only where the triggers are thin enough. To find out where they are, you can use the ULTRASPEEDRUN mod. If you already know where the trigger is, you need to do the following:

1. Get as close to the trigger as possible without touching it.

2. Look almost at the floor, somewhere at 25-30 degrees.

3. Take the blue rocket launcher, jump up and almost simultaneously press Right Click-Left Click-Whiplash. Be sure to do it in this order!!

If you did everything correctly, you should move forward a little without activating the trigger. Then press Right Click to unfreeze the rocket and that's it, you made the trigger skip.

I hope I explained it clearly🙏