My guess is some sort of outboard digital consumer level processor. Possibly involving the guts of the 997 (e.g. multiple HDMI inputs and a mic input) and 7 channel analog output at line level).

This would meet the needs of those who have older systems that cannot process the new signal formats but have analog input. It would also work for those who want to run a home theater bypass for music.

It would be even better if it provided the video processing out of the 997 as well. It could have multiple HDMI inputs and output HDMI, DVI and possibly component.
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Living Room 24x18 open 1/2 flight up to a raised dining room/hall 24x12
Outlaw 976 pre-pro running 5.1 system
Outlaw 750 for Artison Masterpiece LCR and 2 NHT SuperZeros rears
Velodyne Servo FX-1200
LG OLED65C8PUA via HDMI2 to/from 976 HDMI ARC
Roku Ultra
Samsung BD-D5500 BluRay
Amazon FireStick 4K to 976 Aux HDMI input for Amazon Music Ultra