Indeed. There’s also the fact that cutting a stone that isn’t put into a wall already is a time consuming, and difficult task. This is with ideal conditions, a good place to cut, and without worrying about damage to the surrounding materials. Now when its in the wall already? You run the risk of messing up not only the stone you just laid, but the one to the side and underneath it. You can work on the open faces if it’s in a wall, but if it’s on the front face and touching other stones? And it’s getting covered? That’s gonna be a no. Waste of time, even without any breakage.