There are panels of various F-35 LO coatings mounted on a beach in Florida (I think) to figure out how the maritime environment affects it. Both NAS Pax River and Eglin AFB are on the coast and LO was considered during Initial Sea Trials and will be looked at again for the next trials.
I'm sure the UK maintainers in the US are getting plenty of experience on LO maintenance, although obviously don't have the background on F-22, F-117, B-2 etc of their US colleagues.