My suggestion is that you set a ctype on piston or frame, i really don't care, but whatever your ctype is set on is what it stops at. So if you set the ctype of (lets say frame for now) to diamond, then you keep going up or whatever direction till the frame hits diamond. Simple suggestion.
have you even played recently? the new piston/frame idea moves diamond and all other solids... i doesn't move walls but instead destroys itself. I need an explanation on why you COUDN'T do this... you added on my other thread once again making no sence, and actually are starting to piss me off.