there are people here who have experience with engraving painted mdf
which setting is used for this (have a totem 5.5 W and what are critical points
would like to hear
I’m not familiar with a Totem 5.5W, but it must be a diode laser, and as such it is going to depend on what kind of paint, and what color, how thick. People will likely need that information if they are going to be able to offer any helpful settings.
Also perhaps you could provide what your desired result is. Do you want to discolor the surface, Engrave to a depth, Cut (Not likely with a 5.5W laser)?