Good point. I think the potential of a condensation issue would be more problematic than that of heat transfer. If the sealant was applied in low humidity environment, condensation would be minimized. If done in a higher humidity environment there could be condensation whenever the RCM is cool. I don't think that sealing the RCM is necessarily bad from a heat transfer perspective since the design of the RCM's housing provides no intentional means of convection, other than any tiny gaps between the tabs and flanges of the housing and RCM assembly. Though plastic is a poor conductor, I'd imagine that the RCM is primarily cooled via conduction through the housing. I'm not sure how hot the relays get, but I'm guessing when functioning properly they shouldn't create all that much heat. I might just leave it as is as an experiment, since I'll be carrying a spare in the future. What do you think?