RF triangulation exists but requires either law enforcement + carrier cooperation or specialized equipment you probably don't have.

GrapheneOS doesn't include Find My Device because that's Google's surveillance infrastructure. No backdoor location tracking—that's the whole point. Privacy has trade-offs.

The good news in this case: GrapheneOS or not, if the radios are on, the phone is transmitting.

Your phone is still transmitting even when idle:

- Cell tower pings every few seconds (network registration)

- IMEI/IMSI broadcasts during those pings

- WiFi keepalive packets if connected

- Bluetooth advertisements if enabled

- Background RF noise from oscillators and processors

If the phone is nearby, here are some things to try:

If you've got WiFi on and it's connected to your network, check your router admin panel for connected devices. You can also use arp -a or ip neigh to see if it shows up on your local network, or try pinging it.

Bluetooth on? Use a BT scanner app on another device. Walk around and watch the signal strength. Range is about 30 feet. I've found lost earbuds this way.

Hope this helps!