Hi,
while not 'formula axis correction' there is a very useful software utility I use for making circuit boards called Autoleveller.

The blank PCBs are not exactly flat no matter how hard you try by skimming the table, vacuum hold down, you name it.
Autoleveller, theres a freeware and subscriber version, probe the PCB blank on a mesh pattern and then applies corections
to the Z axis of your etching/engraving Gcode from you circuit board program.

With Autoleveller I can successfully isolate route a circuit board with 0.035mm copper layer (standard 1oz board) by taking only
a 0.05mm cut. Never been able to achieve precision depth cuts like that. Now making SMT boards with 0.2mm traces 0.2mm apart.

Probing a big area of MDF would present a few challenges and you would have to pre-process your G code before running the job
but otherwise its indentical to making a circuit board.

Craig