Only your opinion, being not really aware of how it works.
The reason Volumio does not support VM is because no one has any idea what an “aplay -l” in any kind of Virtual Machine is going to display as alsa card info. So no one will be willing to create an alsa card profile for YOUR undefined installation as a patch for Volumio.
Trying to predetermined every possible combination of device and code it into some database to “support” it sounds like a nightmare?
I do hope this piece of software is smarter than that?
Anyway, the issue isn’t VM specific, as @renne is passing through the card, it would be just the same if volumio was running on bare metal. That is the entire point of pass through!
You’re welcome to design something “smarter”, with your knowledge of x86 hardware and alsa that should be a piece of cake.
As there are currently exactly zero x86 developers left, you won’t get it done otherwise.
this would be “HDA NVidia”, to be configured with devices 3,7,8,9,10,11. Called “HDMI0” to “HDMI5” according to my old notes. Best guess for 2-channel would be HDMI0, no guarantee tho, needs someone to test.
Whether all devices are implemented is hw build specific, but volumio does not support multichannel anyway.