[H-Man]

You could actually do the throttle adjustment mechanically now that I think about it. You would need the pully the throttle cable turns to be connected to the throttle body by a differential or another mechanism that would enable something as simple as an electric motor with limit switches (when at the right position, the switch cuts power to the motor) to turn the other part of the differential so that when switching to 13:1 mode, it would close the throttle the correct amount when the VVT solenoid is actuated. The VVT solenoid could be actuated by another switch or by the ECU.