Summary

TL;DR needed something very flat and exceedingly simple, to mount a small TV to a wall.

Needless to say, do NOT use this for any big or heavy hardware.

There are similar designs out there, which inspired this one, but they all appear to be either more complex, thicker, or are designed to bottom out with some sort of stop, which leads to the fit being not tight and wobbling, all of which are not desirable for my use case.