This is a re-mix of BasBasti's Raspberry Pi Display wall mount. I re-created the design in fusion360 so I could tweak the mounting so the screen can be mounted upside-down. This helps if you need better contrast dynamics for taller or shorter people.
In order to use this, you must mount the rpi upside-down on the screen board, by first removing or bending carefully out of the way the POE pins. Then it is possible to make the pi mount much more compactly