This tutorial is created for new Syobon Action speedrunners
Basically, the level 4 wall jump glitch allows you to warp through the ceiling and get on top of it. Then you’ll just need to go straight to the end, with no worries of facing any of the traps at all. It can be carried out in two ways:
The first is simple: You just squeeze your way up. Check out any speedrun with a decent ranking for demonstration. While it is easy to perform, it is not the fastest possible method.
The second version involves jumping onto the ceiling directly using a position-perfect(not sure if it is pixel-perfect) jump from the ON-OFF switch. Top speedrunners all utilize this trick and the detailed setup can be seen here:
https://www.speedrun.com/syobonaction/guide/6ccun
Happy speedrunning!