Eventually replicators that can make other replicators would get invented and then who can or would care to enforce those laws?

Everyone has access to the "copy / cp" commands, yet the USA to this day criminalizes its use on certain digital files, at the behest of the (relatively small) Copyright Industry. I have no doubt that a working "copy, but for physical stuff" would be criminalized in the same way, this time with massive physical goods industries pushing for legislation. Enforcement would be draconian.

> Enforcement would be draconian.

Or at least some industry advocacy group would resurrect the "You wouldn't download a car!" ad campaign.