I watched all three videos last night, Gene's, Erin's and that Alexander bloke's. He really is a piece of work. He is still insisting that impedance wiggle is due to the feet being off, despite Erin proving it isn't and that it goes away when you place the speaker top down. Aby how I doubt the issue is glaringly audible, if at all.
He should be far more worried about that broad rise centered on 4k, with the tail off in HF response following it. That is the sort of response that sounds awful, and one I would not tolerate, and certainly not market.
The nearest speaker that I have to the one Erin tested, are my surrounds. These were designed and built in 1984, so 40 years ago. There is a slight dip centered on 800 Hz, but that is not highly audible. There are no resonant wiggles in the impedance curve. These are high powered speakers and can deliver high spl. F3 is pretty much identical to those Tekton speakers. I know which of the two I would keep.