The fact that this could only work in 100% locked down ecosystems was my thought too. About cutting the part up, that seems to be what this particular paper is most proud of: they did a bunch of math to make some codes that they could still figure out even when they were cut into pieces and mixed up—like if a person broke their printed part after using it. Sort of like error-correcting codes I guess, but able to be reassembled from fragments.