Depending on what all the computer reads I would think someone could engineer a solution to make it a mechanical linkage. As long as the TPS on the gas pedal was still able to read and showed the PCM that it was going to whatever % of throttle position. I don't know if the PCM reads what the throttle actuator is at in % but if it does, it would need to be rigged up to where it would still function back and forth, it just wouldn't be able to move the throttle. To me, I would imagine that your delays with the DBW system would be virtually gone.