I don't have limit switches on my laser machine.
I don't find it to be an issue to just jog into my 0,0 corner. I can do that using the mouse and/or keyboard keys and fine tune the position. A press of the b key turns the beams on momentarily so I can check the 0,0 position. Arrow keys alone or with Ctrl allow me to finely tune the position. Then a press of the r key to reset to the new home position.
I'm always testing something on my laser machine and often times I want '0,0' to be out in the middle of the material somewhere...so I set that as the new home position. Probably for that reason I have not felt the need to add limit switches.