Hi A_Camera
The front of the machine is normally closed, so the copper shavings do not come near me. I can control the depth of the milling so that the tip of the cutter is mainly in the copper-PCB bond layer rather than chewing up lots of resin and glass. Fairly obviously, this is not a router; it's a VMC. I do also have a dust collector which I use sometimes - especially with Corian.
Skimming 0.01 mm is done mainly to remove minor defects like the bumpy sides of drilled holes. I do start with a skim of about 0.2 mm to get the 'flat' surface. I may repeat with a skim of 0.1 - 0.2 mm when I reload the vacuum table onto the mill table anyhow.
I can't use the autoleveller as I use Mach3 and an ESS, so I have to go for a hardware solution. It works.
Cheers
Roger