The container is used to ship the tooling, you could purchase the raw material local to site and build what you need there.
Sorry, obviously wasn’t clear enough… the jigs to build the panels on are larger than the containers
https://www.facit-homes.com/building-process shows a house being built of boxes made from CNC-cut plywood. The trade-offs are probably a little different than the "whole wall at a time" prefab panels; a little more local labor is required to assemble, but transportation burden is a single delivery/pickup of the microfactory and a supply of plywood instead of shipping the wall-size panels that need a large crane to move.