Many people find though that people who hone professionally have standards which are comparable to their own. You may even yourself someday find someone who hones razors exactly the way you like them - and even though they are not judging whether the blade can shave you, they don't have to because both of you share such similar standards. Shaving is personal, but it's not like everyone has such different DNA that nobody can comfortably shave with a razor honed by someone else.
As to the original question, I have always wondered this about everyone who hones a lot. Unlike you, I also know why I wonder about it - it doesn't make sense to me how they can do it! But I also haven't honed a billion razors so I don't know what I don't know. Though I am still curious, it is not a question into whether they can perform all these shave tests, but rather how they do it - which really is just a trivial curiosity for my part. Because as long as it shaves me well, I'm happy :D
edit: of course, if it doesn't shave me well I'll either try another honer or pick up the skill myself (which I have) as pcb01 has done. I can't really make someone hone & test the way I necessarily want them to, I just have to try what they can do and decide whether I am happy with it