some msd/o2 sensor experience needed

Hum... I'd think it'd read rich at idle with a lot of overlap cause you usually have to run it rich with a lot of overlap, but I don't know that unit so I can't say positively. I have mine wired to a main B+ block I installed to power all the peripherals and don't have any problems, but it's not the same unit as you have either. I imagine their worried about noise generated by something else affecting it. Generally a good capacitor like the kind you use with high power stereo's will kill the noise
I'm really looking at a way to use it more for test & tune than a permanent mount ? Use little motorcycle battery
(No interference) and put sparkplug in bung when not in use. I could weld bung in girlfriends Barracuda and tune it also?