All Pixels were however, once an attacker has taken over a baseband via a remote code execution exploit, they could potentially have another exploit for the OS. Hardening the OS including drivers against exploitation from hardware components is often overlooked. Drivers can accidentally trust hardware.

GrapheneOS can't directly harden the firmware/hardware itself, but we do harden the OS against being taken over from compromised firmware/hardware in these situations.

Therefore on the OS level it was mitigated against yes.

Then once the patches were available we rolled them out instantly.

Something you need to be aware of though is while this particular exploit received a lot of attention, things like this are commonly found in security bulletins and updates and can only deal with known knowns not known unknowns. The latter requires constant vigilance and GrapheneOS goes a long way in ensuring best protection from them. We are not currently aware of any in rhe wild vectors compromising the OS.