CopperheadOS is a proprietary fork of legacy GrapheneOS code with most of the legacy hardening dropped due to lack of proper maintenance and it includes no substantial hardening. It also includes tracking in the updater to enforce their subscription fees (which is an exorbitant amount of money by the way, $150 for 3 months).
It's now a scam project focused on attacking GrapheneOS and harassing developers, as evident throughout this very thread with their usage of sockpuppet accounts.
Nice first party links. The Copperhead CEO challenged Daniel to validate the legacy/tracking claims publicly and is supposedly willing to put $50,000 to prove it