I've had that video on file ever since it came out. The use of "Silicone" for ANYTHING on a roof is taboo by some on here. But, in that video, you'll see that they advise the use of Silicone for the roof-to-gutter seam on FULL BODY PAINTED COACHES. Lichtsinn RV is about a block from the Winnebago factory and works quite close with them. We toured both facilities during the '14 WIT GNR in '14.
My thoughts are, if Lichtsinn is advising the use of Silicone for that specific operation and, they're that close to the Winnebago factory, that they (Lichtsinn) "should" know what they're doing when ADVISING to use Silicone for that application. When I was about to re-seal/glue the first 5-6' of that joint, from the front cap, I cruised on down to Three T's RV here in Lake Havasu to find out what they used. That repair facility is also closely tied into Winnebago operations. Their advise, SILICONE for full body painted coaches.
So, just some info here.
To the OP, if you do watch that video, and your Adventurer is NOT A FULL BODY PAINTED COACH, then use what they advise or, what's in the call-out sheet. Good luck.