Arduino for STM32

You are right: I used a 6mm MDF plate (called screen printing plate) - and leveled it with a 12mm bit (and drilled some holes with drive in nuts):
https://photos.app.goo.gl/CBCPTReJS4NYQVMC7
Done within 30 minutes and a perfect surface.

BTW: Like in your video, this is exactly they way I did (auto level)