I love the ingenuity but in this case it is simply not needed. To adjust the minimum idle rate, I open the throttle body screw 3-4 turns. Then jumper the ALDL A-B and turn the key on, wait 20 seconds for the IAC to fully close, then disconnect the IAC. Then remove the jumper and start the engine and work down from a higher RPM. Set the idle RPM for 750 rpm in P/N with the IAC closed off. Then when you reconnect the IAC and restart the engine it will idle at 750 and a little lower in drive. These older ECMs are pretty leniant with idle speed and setting idle speed control codes.