Why do I keep breaking rocker arms?

A lot of adjuster means a lot of geometry to correct. Angle the top of that push rod further and further out accelerate/increase the lift... an uncle dookie garage trick right ? Jk
Well, maybe you forget. I had the head milled a lot, BUT also it is a reground camshaft, which kinda "undoes" some of what the head milling does in relation to the pushrods.