I am sorry for the delay, it took me some time to set up the test.
@T3P3Tony I did as instructed:
Printer reboot, G28 to home. Delta calibration (G32). I selected T0. I checked the nozzle offset for 9 points, no compensation active. I run mesh compensation for the same 9 points.I did the procedure twice, both times the results were very similar, I don't see any repeatability issues.
Attached you may find the heightmap.csv as recorded during G29.
Also the file manual.csv, contains the offsets as they should have been according to my manual measurements.
(I paid extra attention to the sign, I think I got it correct)