I'm not sure the UV cured resin is UV resistant also. I can't find anywhere that says it's UV resistant after curing. Could it be like baking a loaf of bread, heat is good to bake the loaf, but after it's baked more heat makes it go crusty sooner?
I honestly don't know. Do you know for sure? It might be worth while sending a few e-mails to the manufacturers.
I think you're right about the so what? Mostly I think it's the colour deterioration that people worry about with the fiberglass anyway. It'd take alot of deterioration to start leaking.......
Fiberglass with UV resin and then painted with a marine fiberglass paint. I think that would work.
How long do you estimate an aluminum water table lasts?