I guess that this falls into the category of "ignorance is bliss." I didn't notice anything wrong with the SACD quad version and apparently neither did at least 27 other people. I'll have to listen even more closely.
The opposite L-R array of instruments in the front channels, compared to the stereo mix most of us grew up with, is hard to miss. It's also the opposite of the SQ decode that I have.
The rear channels of the SACD on the other hand are NOT the opposite of the SQ mix, on One Word.
So that comports with the idea that AF reversed the front channels, as Steelydave's analysis indicates too.
The only oddity is that , for One Word at least, it sounded to me like the rear channels of the SQ (guitar-keys-violin) are opposite of the SQ fronts (violin-keys-guitar). I can't say if that's due to the original quad LP being that way, or some post processing. But I'm going to inspect Sapphire Bullets and Thousand Island Park in light of that (both of those tracks are side one btw, while One Word is side two...so, perhaps two different master tapes ...I wonder if issues differ between them?)