Can a WD hitch be hitched at a vertical angle?

As mentioned earlier, the valleys are the issues for unhooking. Unhooking like the pic you suggested is actually easier, as you may not even have to jack the front of trailer up to unhook. If you do, it likely will be very little.

I had just such a setup before I put a carport in. I could back up to the camper and actually engage the bars and the snap up brackets without even using the helper bar. This was with my old dual cam setup.