We have vultures roosting pretty much every night in several trees near our house and - occasionally - they end up on our rooftop early in the morning (see Note below).
I’ve confirmed that vultures have indeed tried to land on my Sky. To prevent this from happening for birds in general, I’ve added 3 spikes on my unit (credit to this forum).
It’s still early, but, so far, it has kept the vultures from landing on it.
Assuming there is room in the top part of the Sky unit why not include 3 capped cylindrical supports, level with the existing surface. Should a user have issues with birds, then the caps should be easily removable and suitable materials inserted. Instead of using galvanized wire (as I’ve done) I would rather that the Sky unit shipped with 3 pieces of pointed harder plastic that, should conditions require, would break before the top part of the Sky breaks off. This might happen if a bigger bird is holding on while flapping its wings (a not uncommon sight with birds in trees).
Such a solution to what is probably a fairly common problem with birds in general would mean much less stress on the gear than the alternative we have now of electric tape, galvanized wire, and cable ties.
Obviously, we who have already received our Sky units will marvel over the fabulous after-sales support offered by WF when they provide us with replacement caps 
Note: The vultures we have are black and turkey. Carcasses are not all that abundant so they have evolved to be gliders to preserve energy. As such they prefer tall trees with open crowns and fairly big (dead) branches. They only end up in roof tops, and weather stations, when they struggle to take off in mornings with no wind or of only low speed.
Edits: Clarification
