Well done, Chris. Very informative!!!!!
We've had excellent luck with hard-chroming the factory cast rockers when using steel cam billets to prevent wear and its a relatively economical process compared to plasma-nitriding.
I happen to agree with you on the forged rockers; Porsche used the cast ones to reduce expenses. I've seen plenty of overrevved engines with bent valves and intact cast rockers to know that they do not always break as predicted.
Cast rockers do break from time to time some of which is due to occlusions in the metal. Many years ago, a gentleman used to X-ray & polish cast rockers looking for durability but they were always too heavy for high revving race engines. Such engines usually received RSR (non-adjustable) race rockers which are forged steel or the early steel adjustable ones. Both have lower MOI's than the OEM cast ones.