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?
That should work fine, and I do remember something about having a good dedicated power supply to it.
One of the things I really like about having the guage is the ability to tune better in the mid throttle range.
Sure, it's fairly easy to tune an idle or a WOT but the middle range is a little harder to get right.
The guage lets you see what is happening with the A/F mixture through the entire range of running.