[JRTJH]

This is an opinion, so it's not based on any "specific technical guidance" from DICOR or ProFlex.....

Silicone is a PITA to work with and even more of a PITA to try to remove. I'd suggest never using it on an RV....

That said, if it's already there, you don't have much choice..... So, if it is silicone, about the best you can do is to clean it well, then apply either ProFlex "non-sag" or DICOR "non-leveling" sealant over it. Span the silicone completely, so the new sealant covers it from one edge of the roof membrane to the other. That way, you're dealing with a "known good bond on both sides of the silicone, so whether the new sealant bonds with silicone or not, there's a watertight seam on all sides of the silicone. Cover the silicone completely with new sealant, don't try to "bead the edges of the silicone" as that won't work.....

There has been some discussion on whether to use ProFlex on TPO and DICOR on EPDM roofing. According to DICOR, either is acceptable and both will give good results if applied per instructions.

Whatever you do, from the picture you posted, you're going to have to leave your slide out (at least partially) for several days before any sealant will cure properly and not adhere to the slide seals through the winter storage.

You may find that at this time of the year, if you're going to be putting your trailer in storage for an extended time, it may be better to cover the slide with a blue tarp or some other type of weatherproofing so it won't leak and then, next spring when the climate is better for curing sealant, do the repair at that time.

Whatever you do, protect your rubber slide seals from uncured sealant on the slide roof or you'll be replacing slide seals the first time you extend the slide and the seals are glued to the slide !!!!!