I've cleaned up the code so setting a screw map entry changes the DRO readout in real-time.
Here are a couple of plots of my CNC error curves with increment=25.4mm (1 inch). Note the 2d-ishness of the whole thing.
To put this in a worst case if I were just drilling holes the largest X error pre-compensation would be about 1.5mm (or 1/16th of an inch for US). Post-compensation error is 2*repeatability + test measurement error (~.03mm).
XAxis Compensation.jpg YAxis Compensation.jpg