Appreciate the continuing reponses.
I wonder if I'm apples and oranges here. I tried File->New_Multi-Track-Session, and it appears to only offer up to 6 channels (5.1):

I've browsed some tutorials, and I do see how some/most people add tracks and build a large total number of tracks in a sessions. I'm different, I think. I have a single input device, and it always emits 8 channels, all the time. I do not have the option of adding tracks "later".
Given the above, do you think Audition can record my 8 channels, or it it beyond its design point? Thanks
The mix selector in the dialogue refers to the intended final output for the session, not the number of tracks. You can add many tracks to a session (don't know the limit, but many more than eight). Once you've got you device inputs set up, you just arm the tracks for recording.
See "Direct‑to‑file recording in the Multitrack Editor" in the online help.