A couple of questions about 5th wheel roofs and sealants.

When my last 5th wheel was about 9 years old I noticed small cracks in the sealant . I washed around all the vents with a scrub brush, let it completely dry and applied Dicor self leveling caulk over the original caulk. I never had a roof leak in the 12 years we owned the rig.
The antenna questions is a good one, I will be interested to read any responses to that.