Can a WD hitch be hitched at a vertical angle?

At that angle, you will have very little torsion on the bars. It is just like jacking it up to assist in putting the bars on and off. The opposite angle is where it would be challenging. I had to back into a site in peastone last year at the opposite angle and it took enough weight off the rear tires, that I had to put the Jeep in 4WD to back in.