I was advised to inquire about this here. Should the driver create two digital devices?

_From the ALC663 datasheet: "In addition to the standard (primary) S/PDIF output function, the ALC663 features another independent (secondary) S/PDIF-OUT output and converters that transport digital audio output to a High Definition Media Interface (HDMI) transmitter (becoming more common in high-end PCs."

More information here. https://bugtrack.alsa-project.org/alsa-bug/view.php?id=5310