Use Lightburn for CNC Controllers (Mach3, Mach4, simCNC ...)

I built a CanCam device profile and looked at S in Device settings. S=1 for CanCam, so I can see that your reasoning is that Smax is 1 for on and 0 for off.

Other grbl flavors use Smax=255 or Smax=1000 and LightBurn gladly manages the variable laser/spindle power requests.

Please create a plain GRBL device profile for use on your project and your laser equipped mill. Please report back with troubleshooting questions if it’s not working.