I would tell FR, NO. It is their responsibility to replace a leak free roof. Tell them that a roof from RVRoof.com will satisfy your roof issues and you do not want your RV back at the factory while you make payments. If this is a dead end than Eternabond tape is a good way to go.
If you want to caulk. Dicor and Sikaflex make good self leveling caulks. This is what you want on the roof but, make sure it is compatibile with your roof material. I know Dicor makes self leveling caulks for fiberglass and rubber/TPO.
2014 Sunseeker 3170 DSF
Dorothy, Garrette and Miss Bella.
Retired and having fun.