Given its simplicity, LaserGRBL avoids as much as possible confusing you with so many configurations. However is still useful to properly set up some information that LaserGRBL can not know about your hardware.
If your Laser does not support power modulation via ttl-pwm with S code, but only ON-OFF operation by M3-M5, please uncheck this flag.
All LaserGRBL feature that require power modulation will be hidden, and laser control will be done only via M3-M5 instead of S command.
Starting from GRBL v1.1 there is a new feature of GRBL called “Laser Mode”. If you have “Laser Mode” enabled in your arduino, all the G0 rapid movement will be executed with laser turned off.
If “Laser Mode” is enabled in your hardware please check this flag, so LaserGRBL will render G0 movement correctly, also with external generated gcode files.