Those dimensions are not the problem.

Its the *tolerance* on those dimensions. The seem to be saying it can build an object to within 0.1mm of a dimension. If the tolerance on say stud pitch would accept 8mm or 7.9mm instead your in business.

Tolerances like a lot of dimensions have ISO standards and I cannot remember what classes as an press fit, which is what I think Lego (or a similar but non trademarked press fit type construction toy) relies on.

Note 0.1mm sound large but it is 0.004". IIRC the difference between a car engine which runs smoothly and one whose fits are so sloppy they leak oil is about 0.003"