Rocker arm wear pattern

I got some custom shims from a seller on Ebay for under 50 bucks that moved the rocker shaft on my slant head for better pattern. It might have been B3, I cannot remember. All I had to do was provide him with one measurement taken with a dial caliper and he did the rest. He got it spot on. But as said, I don't think it's a huge issue. Factory stuff comes that bad or worse and runs for how many hundreds of thousands miles?