On 22 fret necks, there's always a little overhang. Sometimes the neck heel is curved like a strat and sometimes its straight across like a tele. The regular neck joint Ibanez' are curved, and the AANJ Ibanez' are flat. So if you got a neck with a curved end, and were trying to put it into a flat pocket, (or vice versa) you'd have some work to do, either routing the body or shaping the neck. That being said, there's usually enough room on any bridge to accomodate minor movements forward and backward in the neck pocket after you make a custom fit. But the only time you're adding wood is on a 24 fret neck that has the last three frets overhanging. The old RG necks would fit a 22 fret pocket if you sawed off the last two frets and slimmed down the overhang. The heel on those was in the same place as on a 22. So for gemini, if Warmoth would make a square heeled 24 fret neck, where the heel went back to the 24th fret, it would work just fine. It doesn't look like they will, though. So you're stuck doing that neck as a 24 fret extended fretboard on an older body, or adding wood, or having LGM or whomever make you a custom neck.