Coleman/Fleetwood always recommends using the 303 which is used by sunbrella from the factory I treat my Niagara twice a year with it. Just make sure the fabric is fairly clean first. Here is a link to the companies website. It is recommended by Sunbrella which you will see IS labeled on the front of the 303 protectant
We bought a used pup fall a year ago. Used it last spring for the firt time had a bad leak with a heavy rain. Bought a camp dry type product. Covered the canvas hevyly have not had a problem since had a monsoon type rain in FL. last year with no problems. I would say it will be fine. If it was me from tent camping treat it every other year. After all its a tent trailer.
We have been tent camping since about 2003 started RVing 2011..There's a lot I wanna say but Religious post are not allowed.