Warmoth makes Macassar Ebony necks, and to my knowledge, it's
more stable than black ebony.
Personnaly, I wouldn't make a black ebony neck, for some reason I
don't trust it as much as macassar. I also personnaly think that
macassar looks nicer.
I wouldn't have bad dreams at night about a macassar neck
warping. I WOULD have bad dreams about everything else
happening to it though...