>>8859336
Eldars are psyker race, and they can make wraithbone soften by their minds. Unless, of course, if bonesinger hasn't provided necessary holes for wraithconstruct.
Imagine a noble wraithlady who decides to "upgrade" her body in order to satisfy her living husband-spiritseer or whatever who suffers after her death and he don't dare to cheat on her because he loves her even after death.