I also did a hinged wall mounted build, in case you are interested in another option.
https://forums.maslowcnc.com/t/finally-starting-my-build-wall-mounted-and-hinged/1438/13
it uses five 2x4’s (plus some scrap 2x4), a piece of 1/2" conduit as the hinge, and a 10’ piece of unistrut for the top beam. The supports for the conduit hinge are pocket screwed into the wall framing.