We have seen evidence that there is noticable structural flexing of the cabin roof when sailing. Two of the screws at the top of our post would work themselves loose from the flexing. This was due, in part, to the holes being worn out and not gripping properly, but did reveal that the roof does indeed flex. So, I would think it best to leave it in place.
BTW, our fix was to rotate the top flange 60 degrees and drill 3 new properly-sized holes. Holding tight so far...