I can't see their wood quality, but they're seeing what I saw with some of my irons. The initial thinner bevel is less even after some wear, but as the wear accumulates, the line that represents the bevel edge becomes more uniform. Of course, that doesn't mean that the part of the bevel facing us is that uniform.
I noticed in terms of quality that obviously as the surface dulls a little bit, perfection is easier to attain. The super bright polish off of M4 and V11 at the outset is an almost impossible standard to meet. O1, tsunesaburo and ward irons did not provide the same quality and the hock developed a very short term dull stripe from a defect that occurred off of the initial edge and then "healed" itself with wear and the surface was uniform again.
At any rate, some of the alloy irons developed intermittent small chips, but they would come and go with wear.
The interesting things is that if wear was uneven but over a wide area that wasn't abrupt nicks, it didn't really appear as something you could see. In both maple tests, these occurred in the more highly alloyed irons, and then as the irons got "closer to death", more of them would appear. In heart beech on the main test, I didn't see much in terms of defects. I think the wood was just too pleasant to cause it, but it was a little more dry and dusty feeling than the follow up beech test (which did present smaller transient defects in the alloy irons). Strangely, the wood that ended up causing no defects still wore the irons faster. That leads me to believe that very small defects really don't have much of an effect on edge life unless a bunch show up unusually early (which would suggest diamonds).
I think there are mysteries even with the SEM pictures that will make it hard to decipher why each iron stopped where it did. A three dimensional flash-type model that you could turn around and see through and measure would be nice. That's probably a bit futuristic for this kind of thing, though, and the findings are the findings - I'm going to avoid much of the rabbit hole of why because it's less useful than what for someone looking to buy an iron and after this testing is done and results written, it'll probably become a distant memory (to me) because I wasn't looking to change anything. Though I will incorporate the fantastic piece of cast that Phil provided to me. If I find that it actually improves the ward's longevity, it may be a regular finish step for me. The wire edge that's created on the alloy irons is something that on 1 micron diamonds will just never show up on carbon steel or O1.