No one actually knows how to lculate what speaker cable they need

So sayeth The Iron Sheik.  Pro wrestling at its worst? You mean there’s a best?

No one actually knows how to calculate what speaker cable they need.
If listening specifications and comparing data information on all audio equipment was the final solution, many good companies would go out of business. Tube equipment and turntables would be extinct. Specs are important, but audio is listening (to what the end user is happy with). That said, for me a well made, proper gauge cable is all that is needed. 

I've mentioned before (but really, you simply can't get enough of these fascinating tales) that my current speaker cable was chosen because Bill Low, who just happened to be standing behind me at a shop when I was talking about bi-wire cables with a sales dude, personally handed me a set and said, "use these." He said some interesting things like his personal hifi rig is in his bedroom (!), and that some sort of magnetic interference issue was obviated by the separate runs of wire in his Rocket cables. My "Marshall McLuhan" hifi moment. And the cables get the juice to the speakers with aplomb.

Confident and self assured cables meandering with a notable strut is apparently a good thing. (sorry...)

This is NOT in any way addressed to GK. I understand you have your own relationship to engineering and unique undertandings.
b4icu you seem to have a partial handle on some aspects of signal transmission physics, perhaps this link might be partly useful
http://matrixhifi.com/ENG_verdadcables.htm
If not, no problem. Most engineers understand that damping factor is swamped by the nature of driver, uniformly low amp output impedance, little effected by typical lengths of speaker wire.
Best wishes.