Well, I read that article and obviously he doesn't know a thing.
As bore size DECREASES and case size INCREASES, the BEST powders are those in the slower end of the table.
This all has a direct relationship with Bore Ratio. Which is how much volume in cross sectional area the barrel has in relation to cartridge size.
The only thing that article stated was that according to ONE manual, H4350 gave the smallest ES. This would have changed if the test was done in a different barrel or test facility.
It is handicapping the cartridge using such a fast powder, and as case size increases so does the burn rate.
Heavily compressed charges do a similar thing, they slow the burn even further, but this is not touted about generally in fear that people will increase the charge weight and blow themselves up. A gentle curve under MAP is where precision loads occur.
Cheers.