One more advantage of the FoxX (over CrossBreed) as starting point is the leather contour in the vicinity of the magazine release: the former is completely relieved in this area where the CrossBreed is not.
I had trimmed the CrossBreed leather in this area to facilitate access to the grip, but still not enough to prevent the leather contacting the magazine release button, as can be seen (the depression behind the trigger area) in the 1st slide of the October 2 post's PowerPoint file showing the CrossBreed as "starting point."
Can't say definitively that it ever happened, but potential seemingly exists for the magazine to be released by abnormal pressure against the leather backing, an event that would disable automatic feeding if it did happen.
The FoxX is completely open in the magazine release area, making this risk an impossibility while significantly improving grip access. Reference the 2nd slide of February 20's PowerPoint.