There is a version that takes advantage of AMD capable hardware on the Moonlight Discord, (there is a channel for OpenStream), just make sure to select the "computer" emoji to get access to the OpenStream channel once you join.
Here's a direct link to the channel:
https://discord.com/channels/352065098472488960/827929913818218496/828577997618544681
If I'm correct, there is no way to install this version of OpenStream, even though it's much better and pretty stable on its own. In order to use it, extract the RAR file and click on the openstreamapp.exe file.
In terms of audio, although I'm not an expert, it does seem to be dependent on your audio driver. The freeware version of Razer Surround does give surround sound and sounds pretty lossless to me. If it means anything, when it's stable enough, I use it for my audio editing on Audition occasionally, and it works well.
Hope that helps you.