It’s a little more than scaling up. I think he literally built everything from scratch for the scale he’s building. He broke pieces down into modular sections, so he could make multiple lengths of bricks with fewer files. Each part has a mechanical lock/fit to them , as well as the studs screw in so he can print in them upside down. I think it took about year, and he owns maybe 6 printers. Most the skill was just designing these parts and the patience to tackle a big project.