I want to contribute to future speedruns for this game. I hope it will be useful.

I found the bug by accident. To perform it, you need to stand as in the video: next to the wall between the passage and the laser receiver. After this, you need to point the laser at the receiver and wait until the panels are completely lowered and try to push the cube through at the moment when they close. If everything is done correctly, the cube will get stuck in the panel mechanism, after which the panel itself will become transparent and you can walk through it by snatching the cube from it.