GrapheneOS has the standard support for E911 that's triggered when the user makes an emergency call. It enables location services in a special way automatically as it does in the stock OS. What we don't currently do is overriding our 2 user-facing toggles for A-GNSS where users can choose to disable or change the server from ours for PSDS and SUPL if they want (they're still enabled by default), although we've considered adding it.

Another thing we don't currently do is force enabling network-based location for emergency calls. GrapheneOS has network-based location disabled by default. See https://grapheneos.org/features#network-location and https://grapheneos.org/usage#network-location. It's a semi-offline implementation based on the Apple location service with both GrapheneOS proxy and Apple options. Fully offline network-based location is planned. Google's services is fully online and makes the position estimates service-side as opposed to iOS and GrapheneOS doing that client side. iOS has network-based location enabled by default and only added an opt-out a couple weeks ago in iOS 18.4. Google Mobile Services devices have a default-enabled toggle in the initial setup wizard and have the Wi-Fi scanning and Bluetooth scanning toggles enabled by default to make scans work with Wi-Fi and Bluetooth otherwise disabled which is always how it works in iOS.

Google's Android Emergency Location Service is not required to share location with emergency services. There are already standard ways to do that. They added an extra system which sends it out-of-band rather than in the standard way. https://www.android.com/safety/emergency-help/emergency-loca... has more info on that. This isn't included in GrapheneOS but isn't needed for this.