Mine only blocks the bottom half of that one vent. It actually helps keep the iPhone cool while charging. When I use the heat, it's almost always floor or floor/defrost. Easy enough to shut that one vent off too.
You don't have to use ProClip's mount. You can purchase each piece individually depending upon what you want to do. You can screw the dock part to any flat surface with 2-4 fasteners. I mounted the one in my Wrangler to a custom metal bracket. I like their docks, have used them in all my vehicles.
2010 Brilliant Black Crystal Pearl Coat Grand Cherokee S-Limited with various bits 'n pieces... broken in but not even finished!