At the current time, I do not believe that spatial audio works with either YouTube 360 Live Event or Facebook 360 live event. It will work from a file with converter software from the Ricoh site.
See this article for spatial audio for video from file.
As the converter simply converts format, I imagine that Ricoh will be able to support live streaming with spatial audio in the future. I have heard no statement from Ricoh about this. I am just speculating because it seems like it is technically possible to me.
I believe that the Mac will work with mono audio for live streaming.
At the current time, audio does not work at all with UVC 4K. You will need to mix it with your laptop microphone or external microphone.