From the Shift Assist Install pdf (page 7, #40) the diagnostic tool is required to select control type to Forward or Rear so that the Shift Force Sensor voltages will be interpreted correctly. Those voltages are the reverse of each other, meaning that the downshift voltage for Forward is the same as the upshift voltage for Rear. Having the incorrect control type set is likely not ideal...
Which is disappointing. I've been considering getting mid controls, with the idea that I could switch between them without too much trouble other than a brake bleed.