Taking a tip from the horse’s mouth (@jussi_laako in a different thread), I updated the Debian Jessie install on my Pi to Debian Stretch and was subsequently able to load the 3.1 package of networkaudiod instead of the older 2.0.5 mentioned above.
Of course veils lifted, basses deepened and soundstages grew beyond recognition.
But apart from that, it feels good to be up-to-date. 