The Cav Arms lowers are polymer, not carbon fiber, and they have been around for years. AZ company, so not many went back east. The new company started up in OK last year.
The one piece design, with the buttstock and grip in one molding is what makes these so much more durable than the polymer lowers that are then fitted with standard AR parts. They essentialy eliminated the stress concnetrations and failure modes of the polymer to metal interface that plagues the other non-metallic lowers.
The other polymer lowers, I tried them, they do not last. These do.