I understand “home the head”, mine homes with no issues. What is your definition of calipers? My calipers would be useless to do anything with this process. I have a Mitutouo digital 8” caliper. Hold one side of what? Turn the other what? I assume you mean the Z axis lead screws? “Lower the x until resting . . .” ???? X does not go up or down. Maybe what I did is the same thing? I raised Z until I could get a narrow steel spacer under the carriage guides. With X centered, I place the spacer under one of the guides and lowered Z until contact. Moved to other side and repeat. Repeat both sides until level. Question: How high should Z be on first layer? In other words What is optimum gap between extruder nozzle and bed? This would be super simple to measure with feeler gauge.