I found a manual for my box last night, this is correct. I'm not an electrical specialist but I imagine since the system is designed to operate on a range of supply voltages it must be regulated in a way to give the same output regardless, otherwise it would be kinda useless. The manual mentions the part about running 10V minimum supply specifically for applications where an alternator isn't used. I have a factory-type alternator that doesn't charge much at idle but gets going above 1,200 RPM or so like they pretty much all do.
I really have no reason to believe there's an issue with the ignition or electrical system. My maintenance log says I put fresh NGK plugs in about 2,000 miles ago so they should be fine.
Also my carb is performing great, there aren't any flat spots or other weirdness, never has been tbh. My sole issue is getting the WOT AFR where I want it. Something I did notice, if I would get into the secondaries without going fully wide-open the AFR would read in the low-mid 12s. I repeated this a couple times first going to about 3/4 throttle and then wide open and it did the same each time which to me rules out the ignition, at least for now. I'll hopefully be pulling the carb and checking it out this evening. I'm also not going to put it back together until I get a new fuel filter, that thing is long overdue to be changed from what I can remember and is likely also a potential source of my problems.
Trying to address the simple things first.