Inspecting the roof sealant is something you should do twice a year. Why?
Because that is the likely place that a water leak will first develop. Water runs downhill, of course, and a tiny leak on the roof will turn into a major problem within the structure of the RV.
Think about this - one drip per minute (through a pinhole leak) adds up to 1440 drips per day or 10,080 drips in a week.
I don't have time to figure out how many gallons of water there are in 10,080 drips, but I think you see my point.
Closely inspect the roof sealant condition on every protruding fixture on the roof. Any cracks or thin spots can be touched up with the appropriate material. If the roof sealant is peeling or flaking in any way, then the old coating must be physically removed.
On metal roofs I use a 1' wide scraper with a firm blade, like the ones used by auto technicians for scraping off old gaskets. For rubber roofs I made a similar sized plastic scraper that won't cut the rubber membrane.
If you heat the old coating with a hot air gun, it will come off fairly easily.