Just going to put my $0.02 in here. I'm new to TT's and own a 154BH (just picked it up on Friday actually). I was up there checking the "rubber roof" out myself during the PDI. I was actually on a ladder leaning on it with my arms, so not really on it.
The dealer mentioned about making sure if you ever scrape a tree to stop and immediately check the rubber roof out. He said if there's a tear to bring it in for service or you could get water damage.
I'd more likely use this stuff to seal it: https://sugru.com/
I've used it for EVERYTHING. A buddy of mine wore a tool in his pocket that ripped his leather seats in his BMW when he sat down on it. The BMW dealer quoted him some insane amount of money ($600+) to repair the seat. We bought black Sugru (they sell it at Target now) and sealed the tear in the black leather seat with it. It looks awesome and it flexes perfectly with the leather when you sit on it.
I've used it to embed magnets in it and mount things to my walls at home. I plan on doing it in my camper on the walls so I can mount a few tablets for viewing "shows." I say shows because we don't watch TV any more, though they make adapters for tablets that you can plug in an OTA (over the air) antenna coaxial cable and watch/record HDTV signals.
If you have a tear - I'd try Sugru, it's dead simple to work with.
Watch the videos on their website and you'll start to get some crazy ideas of things you can do with it.