I think they don't give a shit about 3D printing, especially in CA. It's not like you're competing with a glock19 type hand gun and cornering this market.
3D gun printing has come a long way in a short amount of time. 3D printed lower receivers can weather several hundred rounds of 7.62 at this point
Rebels in Myanmar were using various 3d printed guns just after the military coup (famously the FGC-9), which is like a PDW form factor chambered in 9mm. The barrels are metal, and i think the chamber as well, but the whole fire control group i think is all printed and of course all the furniture is plastic as well.
https://www.youtube.com/watch?v=2K1qXxONls4