Hello radar_boy,
Actually it is already possible to input individual accuracy for X, Y and Z coordinates, it can be done using "slash" separator in Set Accuracy dialog, for example:
XY/Z or X/Y/Z.
So for "planar" markers you can use 0.05/10000 accuracy and for "vertical" markers: 10000/0.05. I would suggest, however, to use the values that are related to the covered area, even if the corresponding parameter is defined with the low accuracy.