TexasCHLforum.com

So looking at a description of the technology, they use laser engraving. It seems like an easy technology to defeat using some sort of high-strength resin to fill in the engraving.

As was also mentioned, there's nothing to stop anyone from replacing a barrel and firing pin.
Beyond that, these are parts that people need to replace. Maybe barrels and firing pins will get added to the long list of things that cannot be shipped to CA.