I am moving on to the next steps in verifying my analog design, part of which is simulating the design with inputs through the analog muxes from the caraval test harness before layout and parasitic extraction, I want to do a preliminary check that the resistance / capacitance will not impact my circuit functionality. Does anyone have advice on how I can do that in xschem / ngspice? Looking through the caraval repo I am not seeing any spice netlists for the IO pads or anything.