Sounds like you mechanically shim one Z-axis to make it identical gap to the other.
Z_Tilt_Adjust does this dynamically at each print to a resolution of 0.005 mm.
I found my problem. After commenting out Z_hop:10 the bed did not attempt to move down and crash with my switches. The bed immediately started moving up towards the BLTouch. And after contacting the BLTouch the bed did move down a few mm before moving to next probe XY position so the BLTouch probe did not get damaged. This resolved my Z Offset variability.
Now the accumulated error is only across the very short 2.2mm distance between BLTouch & nozzle. Instead of the 600mm distance between nozzle & bed when homing against the microswitches.
I still think a Min & Max endstop position makes sense for the Z-axis. For instance, in a power loss recovery scenario I cannot rely on my BLTouch to set the correct Z-height. I’d have to scrap the print and start over again.
