Sikaflex 221 on End Caps?

[pago cruiser]

96 LY 30.
After spending the better part of today peeling/cutting of multiple layers of Dicor self leveling from the rear end cap, I'm about ready to pull the trim to clean out the old ??? under the trim (on the front it was like white butyl, but tougher), seal the void with Sikaflex 221, and put the trim back on.

Once back on, can Sikaflex 221 be used (successfully) as a bead seal? They do not make it in a self leveling. Rather not use the Dicor self leveling, as every bead on this coach I have pulled has been cracked and repaired with piling up more by previous owners.

When I put the trim on, it will be filled with the 221 before install - unlike the AS factory install. So I think a bead from the trim to the fiberglass roof would be sufficient. The trim is about 1/4" high, so it would be "stuck" to the deck in about a 3/8" area.

Did a search, and while there are more multiple threads on the Sikaflex use, none with details on the End Caps.