Picengravertoo wrote: GRBL PWM will generate the exact same gcode as Analog/PWM will if the settings are the same. The reason I suggested using the Analog/PWM profile because it has more features then GRBL PWM has including the Feed Rate Change. The FRC will add a varible feedrate to each line of gcode to slow in higher laser power darker shade areas and it speeds up the lower laser power lighter shade areas.
You may need to engrave at the Right-45D angle because the 4W focused laser beam may not be quite round.
Every laser burns different, so you will just have to do a trial & error test again with the 4W. Since the EmBlaser's uses the CoreXY belt configuration, the set feedrate relative to the run feedrate is not accurate anyway. Try bumping the feedrate up to 3000mm/min and the Pixel Resolution to .1778.