I'd also suggest that at least one of our designs puts down every kind of resistor in a few sizes, with 4-terminal connections, muxed to WLCSP balls, so that we can measure resistance, tempco, etc., and all sorts of FETs and bipolar transistors, with Kelvin connections also muxed to WLCSP balls, so we can measure gm vs Id, vt, hfe for bipolars etc. - This certainly does not replace the need for probe pads though, since leakage current in the mux, and voltage limitations in the mux, will prevent full and proper characterisation especially for stuff like device leakage currents and breakdown voltages.