I'll say that from my extensive woodworking experience, that the probability of a carving such as these in the sizes most will produce within the limitations of the Carvewright, that cracking from expansion/contraction is highly unlikely. Regular yellow woodworking glue(polyvinyl acetate) is somewhat elastic as well.
Now, the littleboxshop may have a point, but so far, my multiple wood carves have shown no sign of cracking. I even have one small one outside under an eave and it's been good for over a year.