Comment by grapheneos

RCS is fully functional on GrapheneOS. Google Messages is the only RCS available for Android in practice and is fully supported by the sandboxed Google Play compatibility layer. It provides a special for granting ICC authentication access to Play services for it.

Camera features and quality are the same as the stock OS within the same app. Pixel Camera works fine on GrapheneOS.

Cross-SIM calling is better supported on GrapheneOS than the stock OS due to our carrier overrides features for force enabling features which aren't otherwise available.