Printer going outside physical boundaries

HI

I have Anycubic i3 Mega. All works well as long as I use Cura to generate gcode. But my recent project includes a laser cutter hack. So I decided to use Inscape and J Tech Photonics extension to make gcode. The problem is, there is no way to set printing area limits. If the file accidentally exceeds these limits, the printer tries to reach this impossible point desperately until the belt starts to slide on the pinion gear - not good.

According to gcode definitons by marlin there exists a parameter called software endpoints:
https://marlinfw.org/docs/gcode/M211.html
This should clip the movement to nominal limits, but it does not appear to have any effect. I also tried "M211 S1" command but no luck.
Any ideas why the endpoints dont work?