Alan, to me you're post is a bit too much rude.
You speak on experience, so do I. Maybe you've got more, but believe me, I'm far from being a newbie. Keep those "lips", uppercase, "flailing", "blow off", "actual experience" for yourself
I printed on a -lot- of different papers, both from the same manufacturer of the printer (here, Epson) and from 3rd parties. Both consumer grade and fine art.
I heard a lot about paper incompatibilities way back in late 90's/early 2000's. To me it's just the past.
I found Epson papers to be generally not as good as most from Ilford, Canson, Hahnemuhle, other, so please forgive me I just pass over them. I still respect any choice.
Anyway, maybe because I'm an engineer, I decided to make another test just for the sake of it. Epson Premium Glossy.
Result? Same very good sharpness as Ilford (just a very little less sharp) and far worse gamut. Here is why I had left maybe three 5x7" sheets of Epson papers and hundreds of sheet from other makers.
Just a last point. I'm not begging for help: I'm trying to discuss with other people on how to achieve better Pro results on a specific field. I'm posting all the results to be helpful for others. Anyone is accepted and respected but that's it. I don't -have to- follow any advice.
To me you're reaction is a bit too much on the ego side.