Your tt will get a lot more aging than the for at a stick house
There is more expansion and contraction with temperature changes
Road vibration etc...
I never had much luck with Dap and similar home products
However a good grade of polyurethane sealant will work just as well as the name brand RV stuff
It's the same chemical composition
I buy 3M Marine grade polyurethane at Orchard..or buy regular roofing polyurethane at home depot
It's super sticky..does not Set Up as fast as silicone ..But doesn't dry out like silicone .. and it stretches with weather conditions
Buy Dicor RV..or 3M. Etc... But stay away from the cheap home products