I am wondering if i create a huge project above ground at once (say, on pause) with several stone stockpiles. Will my dwarfs use the stones from the (near) stockpile while these get refilled? Or do the stones get designated to the construction and being "forbidden to move for other purposes"? So the stones designated to the construction will stay in place till a mason picks them up for constructing a section.
Motivation: I want to construct a above ground castle with the help of quickfort. So the complete thing will be designated at once and will require 100's of stones. I don't want my dwarfs to walk 100 Z levels down to collect the stone by hand though. I normally build one or several stone stockpiles outside and near the construction site so dwarfs will use carts to get the stones up. Since normally i construct a couple of walls at a time they will always pick the stones from the stockpile if they are near and contain the correct stones.