You may be interested in Eternabond tape. It's safe to use on your RV roof. Some dealers will even install it for you for extra $.
I don't personally have it on my trailer. Yet. I'm still covered under warranty for another year.
I plan to strip the dicor calk (as much as possable) but you don't have to remove any of it if you don't want too. It will bond right too the calk as long as it's clean first.
Eternabond is a 20-30 year product so no more stacking more and more dicor every year.
It must be cheaper for the factory's to use dicor. And knowing it needs constant maintenance they can count on selling lots of new RVs because it will leak eventually.
2015 Jayflight SLX 287BHSW
2002 F-250 Extended Cab 4x4 6.8
Teconsha Prodigy P3 Brake Controller
Reese SC Weight Distrubition with sway control (12,000lb)