Haven’t done that, but currently making a arduino shield that will have easy screw terminals for the touch plate, the spindle pwm and my built in filters which screw in the homing switches and have them work as limit switches as well.Video Link should make wiring neater and easier (doing away with the afterthought wiring of the current limit switches and pwm to the grbl board as well as add the real limit switch function. I will have 2 additional for sale in a few weeks when they arrive. if anyone wants to buy one message me.
As for the E-Stop, being it doesn’t connect to the Arduino; the simplest wiring method would be the one I posted here