I'm sure it works fine, though seems like a lot of money for something you can make yourself in very short order. I made something similar years ago - I milled a pocket into a piece of scrap, milled a lip around the inside edge, and cut a piece of PCB material that just fit into the recess formed by the lip, and glued it in with SuperGlue. Soldered a wire to the copper on the PCB material, and connect that to the PROBE input. If, as seems to happen at time with Mach3, the probe operation fails, an the tool is driven through the PCB material, it simply breaks, doing no harm to the tool. Takes just a few minutes to pop it out, glue in a new piece, and solder the wire.
Regards,
Ray L.