Brent,
Well,you have proven that you are highly technical and not a shotgun novice. But I'm not sure many questions have been answered. There are factors that may influence this discussion which we have not even touched upon such as the length and harmonics of the barrel.

I've been told in previous posts on this forum that gun barrels such as my gunsmith described to me never existed and were never made.

I will point out that in my younger years there was often a consensus among shooters as to who had the best shotgun. I have seen groups of seven or eight men with almost identical guns and one gun shot tighter no matter who was shooting. In those days turkey shoots were held at 50 yards not 35. And a true long-range gun had to perform at 80 yards not 40.
The general conclusion that I have reached is that while internal choke is certainly the most dominant factor, the shape of the bore is the deciding factor.