Since they do this all the time, can they put you in touch with some people they have done this for 50,000 miles ago who will show you the inside of their valve covers?

Will they cover your engine replacement if the paint flakes and destroys your engine, and you bring in the valve cover with flaked paint?

On the plus side, the coating might not be damaged by hot oil, and there's nothing that's going to mechanically wear the paint, like road rash.

Best Regards,
Jim