Tangential to this, if RDNA isn't important for you, for NetBSD 10 I have i3wm with picom transparency with all the tricks working with amdgpu AMD Powercolor Dragon RX 550 4GB ($80), 75Mhz Monitor Refresh, with no configuration needed. It's super slick for a BSD, uses 1.2GB RAM with Claws-Mail, 8 FF tabs, Alacritty/nuShell x3, and Pluma 3 asciidocs running, exceptional I think. i3 takes 143ms to start.
Worked more flawless than OBSD and is a recommended buy/value for many content creation, games, and raylib render spins with NetBSD 10.
So awesome you got the Fury R9 to work too, NetBSD 10 is really suprising me.