Funny you should mention that. I used to be an industrial electrician. Back when my pro band had racks of power amps and lots of PAR cans, we had an electrical distribution box ("distro"). It had 6 ga wire with open ends. I had breakers for all of the common panels and was tasked with direct wiring us up to the nearest panel. (I also had the most common 3 and 4 wire range and dryer plugs I could use as well.)
I had to get pretty creative in a few situations to get us power.
And as a former electrician, and current medical equiprepair guy, I can safely say OPs PA owner is just being weird. You want electrical connection tolerances that CAN make a difference? Work on an EKG sometime. But 120V AC plugs for PA speakers..... nope.