Over the past 2 weeks I’ve added proximity sensors for homing on the X and Y axis (still working on Z but need some more downtime) and I have been pleasantly surprised on the repeatability and accuracy they have provided to the homing cycle and using that as the basis for work offsets. I have both a metric digital dial indicator and a imperial mechanical dial indicator and through 50+ homing sequence tests with controller reboots between some the error is immeasurable on my indicators .005mm and .0008" resolution respectively although you can estimate the dial indicator to .0002". I was hoping to hold .003" on homing but it has proven to be far more repeatable than expected.
For backlash testing using the same equipment I have observed 0.000mm or 0.005mm, on a machine with about 1200 hours on it (Journeyman upgrade X axis is closer to 500 hours)