I can't speak for the Solus GNOME maintainer, but this issue seems to require patches and rebuilds for gnome-shell, gnome-control-center and possibly gnome-settings-deamon. So, I don't know if anyone is willing to do this or if you just have to wait for the next gnome (point) release. Fixes for this seem already have merged to gnome-shell and gnome-control-center main branches.
However, the only way to find out is to open an issue for this on the Solus dev tracker describing your issue and including the links you have provided above.
As a workaround you might install pavucontrol and select your audio output there.
sudo eopkg it pavucontrol