Do as you please but please don't advocate that others follow your example. There are other ways of fixing them. I have had RVs for over 40 years and have yet to have one leak in this area but I have resealed the clearance light many times. You can pull them off and seal the holes where the wires run out (as you know the manufacturer drill a hole about 3 times larger than is needed) and then put sealant around the screw holes before screwing them in. I also have added some caulk around the outside of the lens. My new one has LED, just small dots and then they are sealed behind them.
I personally well keep mine working for other drivers on the road to know they are approaching a wider than normal vehicle coming towards them. I drive a lot when it is dark so I like to let them know about my size.
Each to their own. You asked what they are for and I think I answered that one, not for you but other drivers.
This is IMO
