The shop was very knowledgeable of Cometic gaskets and has prepped engines using them in the past with success. They shared my concern for valve clearances and even thought 0.056” might not be enough to bring it up to spec. In the 2 scenarios you mention neither were a direct result of a the gasket itself. MLS gaskets are not forgiving at all and something as simple as chasing the threads could be the difference maker (Dirty threads = innacurate torque). People are more likely to review a product following a bad experience than a good one.
