How to run automatic mesh compensation using router bit as probe?

I am looking for a way to use the XYZ probe connector on my machine to perform automatic mesh compensation on pcb blanks; you might expect it to work similarly to how the XYZ probe works but over a defined area. After following the duet guide on mesh compensation it appears when you run G29 it defaults to running manual mesh compensation (because no probe is defined?), if this is the case is there a simple way to define a probe for mesh compensation? (also a G92 Z0 command is required before running G29 or else it will try to bring the tool head to machine 0 not work 0)