The laser cutter’s kerf (material removed by the cut) is roughly 0.15mm in 1/8’ plywood. The kerf width changes with material, focus, thickness, cutting speed and sometimes the laser’s mood. But usually hovering around 0.15mm. The beam is conical in shape so your cut is wider on the surface of your material than the underside. The difference, though, is hard to spot.
I have made 0.9mm circles in birch ply and didn’t notice that they were irregularly shaped to the naked eye. I mean, you are limited by the stepper motor resolution but they seem to have a very fine resolution.