Thanks for all the bench work and reporting.
Tweaking on AVFS appears to be the *Brave New Frontier* (or, "We're all beta testers for AMD" :lol: ). The fancy cooling was impressive but as noted under- clocking/volting brings out unseen efficiencies in Vega/Polaris. That's certainly not at the top of the list of many Tech Heads but gives AMD better insight going forward as they bake new wafers, fix bugs and tweak the arch.
I suspect the nVidia bunch does the same thing, but the woods are filling-up with volt- and BIOS Mods for Polaris and Vega. There's a thread at Overclock pushing 500 pages! Manipulating volt tables is becoming an art ...
More than anything, what I believe this shows is that AMD (and GloFo) boxed themselves into 'One Size Fits All' with gaming cards because of varying consistencies in the chips, and just like desktop Zen they were the last picks of the litter behind the big money makers --- enterprise, HPC/deep learning, Apple, etc.