Best roof protection,coating?

I am having a spray on roof replacement done this week on my fifth wheel. It is a product, similar to a bed liner, but lighter in overall weight. I had water damage to my roof and a piece lol wood needs replacement, so while this is being done I chose to have a maintenance free spray on roof applied. 20 year, transferable warranty. No caulking is needed as they spray over those areas.

I will post a new thread when it is completed with pics.