Trailer: Escape#4, 2019 Escape21 DejaView pulled by 2014 Ram Hemi/8sp
Why not both, use the butyl around the wire hole, then use the proflex on the screws and around the exterior perimeter, similar to ETI's installation of the windows, butyl around inside and profile along the top exterior..
"Never in doubt,..... often wrong!"
I've had to replace a couple stove vents, and an electric cord inlet on my Starcraft, they used Butyl tape. Never had a leak in those spots so that's what I'll use. Covered the whole flange with it so the screws went through it.
On edit... Downside, any that's left showing picks up road dirt.