I need to modify the default settings so I don’t have to make the changes every time I boot my GShield v5. I am not able to find any documentation on how to do this. Anyone?
Sounds like you are looking for something that will change the settings in grbl, not grblshield. grblshield (gShield) is just hardware that sits on top of grbl. You might try looking at the grbl github wiki or issues list