KCee I believe tolerances have gotten better, but if you read the spec sheets, they will tell you the tolerance they accept. Usually +-1on all specs, which can lead to a really bad fit. The availability to manufacturer tighter is there, but as you know, the tighter you want, the more you pay and profits are key. The other thing is 99.8% of guys will not know the difference between and have no way to measure it without more effort than its worth. So I still wouldn't be shocked if a head is stamped at 10.5 and 11.9 is pushed through.
I think of it more like TM, Cally, etc are competing in the muscle car ranks, like a mustang, camaro etc and their best are towards a Corvette. Good tolerence is needed, but not demaned like the Ferrari, which would be more like the Honma etc.