You might even want to…uhhhhmmmm… use autoleveling…shhhh don’t tell anybody I said that. Just turn it on in the firmware and use the vbit as the probe. Pete the guy that made the Root CNC told me he uses http://reprap.org/wiki/CNCGcodeController specifically for how well it handles PCB leveling. I haven’t tested them head to head but it sounds like 2 valid options.