Attention vendors....

We need a french cleat type device mount system, that goes on the wall behind the TV near the top of the TV. Strap the device to plates, drop onto rail from above, wires loop down behind the TV naturally, and remote signals if needed easily bounce off the ceiling, or devices mounted sideways for troubleshooting LEDs. Most TVs today mount with holes low on the set, leaving adequate space at the top.

Cleat rail with plenty of screw holes, 6x9ish drop on plates (plastic might be nice not to scuff the paint) with slits for velcro and ties. Longer rails can hold 2 or more devices.

I use the small plates and in wall boxes, and they're fine for arm mounts, but not practical for fixed sets. And the cable guy is not going to take the fixed TV down to change the box mounted on a fixed plate or inwall enclosure.