I bought a set, too, Glenn, as you know. I just don't know if they are helpful or not. My issue that eventually cost me way too many thousands of $$ was corrosion under the skin behind the exhaust port on both engines. Over the years that corrosion ruined the skin and the braces underneath...pretty much all the way back to the aft end of the engine. I was up for trying anything that might prevent that from happening again. So, I don't have an answer yet. Ask me again in 40 years... ;-)
Ed