Yep. As for the making a fortune part...HAAAAAAAAAA HAAAAAAAAAAA you'd have to convince people it's worth the effort and those folks are few and far between, and most of them can do their own machine work.
I'm a details guy. It's the little things that add up. Anyone can do the easy stuff. I'd bet money, big money, like all I have and some stuff I don't, that guys like PBR and PRH and a few others...MoparOfficial...probably missing some names here but you get who I'm talking about all do the very same thing every time they check out someone's port work...they get a finger in the port and check the short turns.
I know I do it. First, very first place I go to, because it's the hardest place to grind and get it correct. And most guys just buff it off and let it go, which isn't a bad thing in many cases. You can loose more there in a second or two than most would recognize.
Before I bought my flow bench I had several other shops with them test my stuff for me and it was hilarious. First thing was a finger up my short turns. Then they look at the valve job.
That's why PBR and his thread is so interesting. I can sit back, read his stuff and enjoy what he's doing. He is explaining it much better than I can. And those who want to learn, if for no other reason than to be better informed when looking at cylinder heads.
The guys who want to improve their heads can really learn a bunch from his work.