If LaserWeb has a feature which turns on the Diode laser at low power for visual framing then ya, that’s more like what should be expected. But, are you sure LaserWeb has that feature? Many CO2 laser machines have a red dot laser specifically for alignment so you would not want to turn on any power to the CO2 laser during framing. LightBurn has a special setting specifically for diode laser framing because you do not want to do this with CO2 lasers.
The laser is not activated automatically because this would be a security issue with CO2 lasers.
The solution is to configure the “TOOL TEST POWER” in the gcode settings and use the “Laser Test” button to switch the laser on before “Check size” and off afterwards.