@Weaver, have you thought about Mini-ITX?
I built a couple of Mini-ITX chassis as Myth TV frontends, about 10 years ago, grew to like it - good choice of cases sufficiently compact to blend in with the furniture under the TV, and easy to choose bits that are energy efficient, hence less need for noisy fans.
This is the site I used as reference and inspiration for my own Mini-ITX builds, as well as source of most of the bits. I know nothing about Ryzens, my build were ION boards, popular at the time. But if you click on ‘Board Finder’ it does seem to suggest that Ryzen boards exist. You might be a bit restricted in choice of cases, but some seem to be available...
https://www.mini-itx.com/My only regret was building one that had an internal PSU. When the PSU eventually failed I was unable to source a replacement as the PSU turned out to be non-standard dimensions, I don’t think Mini-ITX actually specifies a PSU form factor. I was able to repair it, but would have preferred to replace it.
