On the other hand - it would be low hanging fruit to prevent off the shelf printers to print well known gun parts? Much like photocopiers and scanners and printers won't scan, copy or print known currency bills?
> copy or print known currency bills
Currency explicitly embeds detectable patterns to make software detection easy - firearm 3D models don't have any such feature.
> (a) Any business that produces or manufactures three-dimensional printers for sale or transfer in California shall take both of the following steps
This is worded a bit ambiguously: it's not clear whether it's meant to be "manufactures ... in California" or "for sale or transfer in California". IANAL, but wouldn't the latter be unconstitutional inasmuch as it conflicts with federal jurisdiction over interstate commerce? It seems unlikely that California would be able to enforce this against businesses that have no operational presence there, and are merely shipping 3D printers to California from other states.
And if that's the case, the only meaningful effect of this bill passing will be to further motivate anyone making or selling 3D printers to leave California for other states.
Note the difference w.r.t. the ridiculous "California's New Bill Requires DOJ-Approved 3D Printers".
I wonder what your first language is.