I think some of the confusion on this comes from the difference in the engine builder's situation. If you read the instructions that came with my Scorpion roller rockers, it says to add shims if you get more than 1 full turn when torquing them to 20ft/lbs. This I believe, is intended for a builder that is not changing pushrods and is not concerned about geometry.Is it really necessary to use a shim for the pre-load? Why not just add .025-.050 to whatever measurement at zero lash achieves the best pattern? Shims just seems to complicate things as I believe they alter the sweep when the rocker arm now sits at a higher position. Stud and adjustable rocker arms are much simpler and using the mid-lift measurement made my life easier too.
I have to buy hardened pushrods anyway. Since I have both adjustments available to me, why not do it the best I can?
Roller rockers manufacturers should explain this in their instructions better cause I'm guessing it adds to people's confusion.