I've asked this question before and have not gotten an answer, so I'll totally understand if you don't answer it either. Do you worry about the neck being damaged by hanging by the machine head? I would think that the weight of the bass could effect the neck in a bad way.
Each string of a bass is under anywhere from 65lbs-85lbs of tension when tuned to pitch so hanging it or placing it in a stand exerts no more or less tension on the bass than already exists from the strings.

