Thanks Gonk.

Amongst answers to some other questions, here's what the Onkyo "Help" rep said on the topic: "Also AUX2 DIGITAL OUT is fixed at the FRONT DIGITAL or ANALOG outputs there is no way to change that."

They still have not provided ANY information as to what problems various firmware upgrades are supposed to solve - or features that it might add.

I keep plugging... but wouldn't it be nice if a future version of the Outlaw's 886 Guide addressed the topic of firmware upgrades (what they are and how to do them safely at home).