Suggested mainteance for 10YO roof

[chuck1856]

I have a 2007 Couger 5er that we bought last fall. It's mechanically sound but roof was pretty dirty from a few seasons in the woods at a seasonal CG. I'm looking to get things ship shape to enjoy it in the years ahead.

I've cleaned the roof thoroughly and removed the maxivent covers and planning to hit all the vent seams with dicor sealant this weekend.

Next step is something for the overall roof. It's EPDM and has a lot of black specks that faded but didn't remove entirely wish washing. Appears like a mildew on the surface, not the underlying black rubber.

Got two different opinions on treating it from the local RV shops. One says wash and do a treatment...said no need to coat it, if it's still white. The other suggests a coating due to the age. I like the idea of the coating and letting the sun and weather beat up something newer than the 10YO membrance. They recommended Hengs so I have a gallon of that.

Any thoughts on this approach and/or Hengs? Reviews for the coating seem very positive.