I think this whole "raintight" is BS anyway. This is a wet location and if it is outside it will get wet inside. That may just be a Florida thing but it certainly seems true here. It could be humidity that cycles through the dew point most nights or it could be the sideways rain.
If U/L wants to test something they should try a bubble cover in a 40 MPH summer shower or just look at a bell box cover gasket that has lived in the sun for a couple years.
I imagine the whole thing is just trying to get us ready for GFCI protection on outside lighting. I am doing it on my patio but I am doing it with boxes that get water in them now and then. I have about a half mile of #12 THHN in EMT above ground and RNMC underground serving overhead lighting and receptacles. It is all on 3 GFCIs. First tip, always be sure the wirenuts are at the top of the box and pointing up.
