It's not just the cutter, look at the software that controls the laser cutter. MOST use generic programs that are not developed for any if the cutters.
GLOWFORGE developed custom software for its machines. It can vary the power within the same laser sweep. SO 3D Laser engraving comes out fantastic.
Same is true for Formlabs they use their custom slicer program to build the steps for their printer not a generic slicer.