Thanks, that's what I figured.
I did get sent along a good description of how the aerial focusing works; the aerial image is always where it should be (assuming everything else is within spec) and will always appear at its sharpest when the enlarger is focused properly. However the eyepiece being set for a misplaced reticule will affect how sharp that "snap" into focus looks, like trying to focus a camera with the wrong diopter adjustment at the viewfinder. Get it far enough wrong and focusing would be a challenge, if not flat out impossible (as it is for me with an eye level viewfinder and no diopter correction, the image never snaps into focus, it just gets less fuzzy!)
I had always figured you focused your eye on the reticule and then brought the grain to focus matching that. Seems that the reticule is simply there to get the eyepiece diopter set appropriately.
Either way it's an easy enough thing to fix so that I can set the eyepiece correctly and not just "close enough".
Now if only my arms were a little longer. With the enlarger head all the way to the top it's quite a stretch to look into the focuser while reaching up to the focus knob on the 23CII-XL. Do-able, but a stretch!