I will be interested to see what results you guys have trying to adjust these.
I turned the setscrew at least 20 turns with the engine running and a meter attached, and did not change the voltage at all. The only difference I could see was with key on/eng off, where clockwise turns raised the voltage. The reading I saw under these conditions was a fraction of running voltage. I finally stopped after raising voltage from about .017 to .2v. Running, on the other hand, was below .7v at idle both before and after adjustment attempts, and simply installing the pot solved both stalling and hunting to 2k rpm sysmtoms.

I wonder if this relates to what SteveB mentioned about .7v being the magic number to get below to send a signal to the ECU.

I had mostly put this issue on the shelf until I addressed some other problems and will pick it up again after I get the head back on (hopefully) this weekend.