Yes and no.
The plastic masking comes off all the materials. I use paper masking on leather, wood and plastics.
As a rule I try to engrave/score/cut vector designs without masking on the two color. Only once have I got discoloration//char from doing it this way. It was a marble looking two color and for some reason it wanted to flare and flame (suspect something in the materials to make it look like marble).
If there is a raster element, they tend to sweep over the entire design and this can discolor some metallic looking two color. The masking allows for a light sweep of the laser on the near white areas without taking the shine off.
I glanced at the parameters I listed above. They have been fine tuned somewhat. I have been using a lot of acrylic lately and played with the settings (from poor cuts) until I locked into these below, which are used no matter what color combo I have in the machine.
engrave 1000/60 @195 (for 0.060 thick) - this leaves glue and spotty misses if acrylic is masked- so still 80-100 if masked.
score 300/15
cut 225/full (can use 100 instead of full but some colors will not cut good then so I just use ‘full’ all the time)