I've recently installed the latest Kalico release on my printer and it appears that "x_offset" and "y_offset" fields are not used.
I've checked with dockable_probe.py and see the following lines:

self.x_offset = config.getfloat("x_offset", 0.0)
self.y_offset = config.getfloat("y_offset", 0.0)

I don't see any usage of these variables somewhere.