CalyxOS

Sits in the gap between LineageOS and GrapheneOS: more privacy tooling and microG out of the box than the former, more device tolerance and convenience than the latter’s purist stance. The trade is that bolting in microG to make Google-dependent apps work is a real attack-surface and trust compromise GrapheneOS deliberately refuses. Choose it if you want a usable de-Googled Pixel without fighting your apps every day. If you want the hardest baseline, GrapheneOS is the stricter pick.