Recently I experienced some problems when editing parameters for the coordinate system.

I use probe to measure the rotation of my part and I set the rotation with G10 L2 P#<_coordsys> R#<_measure_rot>

That's working as expected, but when I edit any parameter in coordinate system dialog, the rotation doesn't fit anymore and there is a noticeable difference than before.
I found the decimal places of the rotation as the problem. It is limited to 3 decimal places in the dialog, and using the dialog to edit any parameter, the decimal places are cut after 3 decimal places which leads to a inaccuracy of a few millimeters on large parts.

So I recommend to increase decimal places for all rotation parameter at least to 6. Otherwise on large scale parts, the rotation is to coarse.