I cannot locate the effect/feature for the life of me.
Information is scarce, out of date, and misleading.
You're not kidding. This is what happens when you cut and paste from old manuals without actually looking at the software!
The closest you get to any sort of effect like this is the Graphic Phase Shifter, or the Doppler Shifter. As the Binaural Auto-Panner, it hasn't been in Audition for several versions, I believe. And no, features aren't limited in the trial.
IIRC, the Binaural Auto-Panner as a name was dropped some time ago, because it sounded a little 'new age', if you see what I mean. Something you'd put in shareware, perhaps, but not a 'proper' program! Without going back and looking at exactly what was in the autopanner, I'm not sure how much of its functionality is still present.
This is a feature that I really enjoy using.
In fact, I would buy the software to use it.
...And will not buy it on account of it lacking the feature.