They don't have a relevant item in the FAQ but it sounds like they place each block manually directed by a schematic overlay
2. On Exactitude of Science - Borges.
https://kwarc.info/teaching/TDM/Borges.pdf
The story...describes an empire where cartography becomes so exact that only a map on the same scale as the empire itself will suffice. Later generations come to disregard the map, however, and as it decays, so does the land and society beneath it. [Wikipedia]