Any chance we can get this feature implemented/merged? It seems the feature has already been developed:
					GitHub - xhbl/LibreELEC_dualaudio: LibreELEC  Dual Audio Project Repository
					
			LibreELEC  Dual Audio Project Repository. Contribute to xhbl/LibreELEC_dualaudio development by creating an account on GitHub.
					github.com
				
In my use case it would allow simultaneous output of a spdif pi hat and hdmi audio. Since this has been a patch since 2014, I suspect a lot of users could benefit.