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.