What you have written is interesting. But, whatever manufacturing or consistency differences may exist between these powders, in my guns over my chronographs, I cannot measure these characteristics, therefore, are these differences without any distinctions?
When it took one grain more of H4350 to have the same velocity for the same components as IMR 4350, is that significant? I am going to say no, because it takes only a couple of kernels of powders to make a ounce grain. I do not consider that a significant difference because I have seen the same weight differences between lots of same brand name blended powders.
Advertisers can spread the thickness of a human hair to bridge the Grand Canyon, the long way! Take for example the threads which go to hundreds of posts, claiming the 270 Win is better than the 30-06, or visa versa. Where did these posters learn these claims and are the differences significant, as they claim, on target? Posters were taught by Corporate Advertisers that their products, with less than a human hair difference between the competition, are
significantly better, and hardly any test the claims to see if there actually is a difference.
Until companies can put out a product which I can see differences between it and the others, using the test instrumentation I have, which is components, rifle, and chronograph, than I am going to tell people: buy by price.