I wondered about this. I feel very confident about my tune, but I do wonder if my surface Ra was good enough for the FelPros or not. They claim 60 Ra or smoother. I never checked because I didn't have the gauge. I just took my machine shop's word for it that the surfaces were smooth enough.All you have to do is move some gas one time across the MLS gasket and it is compromised.
From wherever reason, a tuning hickup, ect. They are never going to be right until changed
When the hot combustion gas flows betweens the layers the embossments loose their spring
Replace, make sure everything is true and the tune is on point and you won't have issues