Conductive touch probes? That idea has been in use for ... I dunno, maybe 50 years or more. I really haven't a clue when it was first invented. Does not work on insulators of course.
Conductive touch plates for the axis? Yeah, just as ancient.
It might be amusing to do a patent search on the idea, to see how many times it has been patented. Probably would not put the PO in a good light, but I have not bothered.
cheers
Roger