Bump stop and x and y zeroing

I like that startup trick.

Will you lose the G28 setting after turning off the controller? If so then it’s the same as losing power during a carve and really no way to find that zero point unless You Drill down at the beginning and make a permanent mark and can still be off if your changing bits, right?

No.

G28, G30 and WorkZero is stored permanently (untill reassigned) and are persistent across power cycles. Their values are stored as an offset relative to MachineZero.
When a machine is homed ($H) MachineZero is set and allow G28/G30/WZ to be consistent.

Without a homing cycle MZ will be where ever the machine is at start-up and G28/G30/WZ location will be inconsistent aka useless.