When I try to render using either opus (not libopus just opus) or vorbis for the audio I get the following message: "Unable to start VoukoderPro: Undefined error!". This error seems to happen no matter the bitrate or the rate control setting (the latter setting opus currently doesn't have atm).
The video is set to AMD HEVC and container is set to MKV in both cases, although i've tried just rendering the audio only directly in their native containers (opus and ogg) and it still gives me the same message. I'd include a log file but as far as I can tell Pro doesn't have that yet.
On a related sidenote, i've also noticed that for some reason when using the ogg container it says vorbis isn't supported even though it's the native container for vorbis.