A while back, I built an adapter to take a 10K Expression pedal and convert it to CV (0-5v). I know this isn’t useful for Dwarf and Duo users at the moment, but might be of use to DuoX users.
I didn’t see a way to attach a schematic here, but I can provide a KiCAD schematic if anyone is interested. You could modify it to match the pots on your own expression pedal.