Sorry, but you are wrong. It's every rocker out there. It's not a Crane problem. It's a Harlan Sharp problem and their answer for everything is use a lash cap. It's a MP problem because the ductile iron rockers need to be corrected.
Hughes is no better or no different. You, me and anyone else just bolting on rockers and thinking they are golden has no business doing engine work.
Face it. The fact is I know engine builders to this day who don't understand rocker geometry. It is what it is.
If you use anything but dead stock everything your rocker geometry needs correcting.