Dear Lightburn Support team, can you please able to help me in this ?
When you click on the Home button in the Laser window, Lightburn sends a $H command to the laser. It sends nothing else and the Homing cycle is entirely within the laser controller. Lightburn has nothing to do with that.
I see you posted $23=1, then later $23=0. Do not change GRBL parameters unless you know why and what the result will be. This is especially true if someone is trying to help you diagnose a problem.
Did you make a backup of the parameters before you started changing them? If not, your only recourse may be to restore them from the controller memory.
No, it only impacts repeatability when doing the same job over and over. There are lots of machines running without limit switches. As long as you are careful, you should be okay.