The AANJ is not an option direct from Warmoth. The 24 fret option is a fingerboard extension. It is quite different from an Ibanez AANJ.
What I ended up doing was creating my own by choosing a contoured heel option, using recessed ferrules, and sculpting the rest.
This requires you to redrill the holes closer to center, as the ferrules would come out of the sides of the neck joint.
I used stainless inserts while I was at it:
It's close in comfort, and provides more mass at the heel than an AANJ.
It really wasn't bad at all. I would not try it without a drill press, though.
I used a 16" radius block, used for sanding frets, to keep the neck level with the drill bit on the press.
I clamped the neck, to the block, to the drill press table, and had at it with a 1/4" drill bit.
I used a walnut 1/4" dowel rod. Closest I could find to Wenge.