I guess it depends on what bike, what year, what valve's and of course, how your particular set of collates were manufactured. I never had an issue with a gen 1 kit or a recent install that I did for a client. Sure, the variables are high, but still the OP's comment "pain to get off", I just never saw that... Though I also have good tools.Mike did say it was true at one point in his above post.
Well, I mean if you've got bad rockers, the wrong oil can cause them to flake from not creating enough lubrication between the lobe and rocker.I've followed the rocker issues fairly closely for the last five years and I don't recall as absolute fact poor clearances has been the #1 reason for rocker flaking. It has been suspected in some circles as a contributory factor, but no one will comitt based on factual data this is the case.