Cables moved by piston do not update model (though any stationary, adjacent cables do update).
Versions:
This mod: 0.11.12
Minecraft: 1.12.2
Forge: 14.23.4.2705
rubensworks commented
I'm surprised that this even works, it used to crash (#309). In any case, this is unsupported behaviour for now, so only use this at your own risk, major problems may arise with this until we officially support it.