@SanderLPFRG It's listed as 'technically possible' in the restrictions section, here: https://docs.duet3d.com/User_manual/RepRapFirmware/CAN_limitations#semi-permanent-limitations. I'm not a programmer, so I don't know what firmware changes would be needed. One for @dc42.
I think the main reason for no analog support on toolboards is slow update. A digital signal is faster than an analog signal to compute and send over CAN, particularly when you need to control motors to stop eg when homing axes. An FSR board that outputs a digital signal might be an easier option, eg https://github.com/JohnSL/FSR_Endstop, then you can use probe type 8.
As far as I'm aware, the SZP sends a digital signal. The MCU on the board is dedicated to converting the eddy current reading, so there is less overhead.
Ian