Buddy of mine swore by wrist gauges till he kept bumping his into a pipe and lost his read.

Man, I have to push back on this one. Cups absolutely can last on a high mile truck if the bores are clean and straight, and plenty of guys get 50k plus out of them when the actual problem is just the cup seals. The real issue on most of these is guys slap cups in without checking if the head is cracked or the bores are pitted, then they blame the cups when it comes back. Doing a pressure test and a good look at the bores before you commit tells you whether cups alone will hold or not, and that saves the customer from paying twice. Pulling heads on every single one just because the odometer says 210k is throwing away the owner's money when a proper cup job would have held fine. Your comeback case sounds more like a bad diagnosis up front than proof that cups never work.