Over the last 20yrs or so I’ve owned 4 trailers of differing types that had rubber roofs. None leaked, none experienced tears, all ran black streaks down the units at times, all we’re out in full desert sun 365 days a year. Oh, I never treated any of them with anything either.
With the above said, I had a hard requirement for my current coach to be one with a non-rubber/EDPM roof. I always hated the thought of that thin stuff up there, it just seems cheap & fragile. Having a solid rooftop makes me feel better & that’s a good thing regardless of the fact I never experienced a rubber roof issue.