I have been undergoing a similar issue, You can see my post in class c. I have never used dicor on the vertical surfaces. I use what Winnebago uses. I believe it is a high end silicone caulk. (nuflex 313) I know, many will say never to use silicone on an RV. But that is what the local RV shop told me to use, and so far, after 12 years, no problems, in terms of pulling away or leaks.
That said, I have been in contact with dicor, for questions I had about dicor roof lap sealant. They have been most helpful and responsive. My suggestion is you e-mail them and ask
