Do any of those people you mentioned do testing like this? No. They don't. Neil did.
Neil felt an overwhelming urge to have people believe as he believed...... and would spend innumerable hours making data and charts presentable to support his beliefs. All good, the man was bright and was very charismatic. A pleasure to argue with, he indeed had a following. You as an engineer know you can make any data set sing whatever chorus you want, data manipulation is how many engineers support their careers and how bridges are built that fall down. I am not accusing, just a fact of life.
The one thing never recorded was exactly what pattern percentages a singles, 18-21 yarder, a 22-24.5 yarder, a 25-26 yarder and a 27 yarder actually need to pulverize lightly or pulverize completely targets from all those distances. I don't think I've ever seen the hard truth printed, just opinions.
Does the 18 yarder need the same choke\pattern percentage as a 27 yarder? Probably not, does the data have any conditions regarding that? Nope. Take singles, does a "D" class shooter even have the skills to discern the difference or even make use of a top notch performing combination?
"Full for Everything!" is a rallying cry heard, does it work? Absolutely, many decent shooters follow that prescription. Would they shoot higher averages with a poorer performing shell that would open the pattern? Meh..... does it matter?
A person has to make the decision to have barrel work done and then believe in it or not. Smoke in the air gives me confidence, especially from the 27. No charts, no graphs just perception and endorphins. I see more smoke with barrel work.