Here's a fun fact about Bluetooth, with the BLE standard apps can communicate directly with devices, and essentially hide from the system of your phone.

I wouldn't trust airplane mode to not transmit any data, so I leave all devices at home when protesting, etc.

I would also recommend putting a rock in your shoe, to throw off your normal walking gait. They can identify people by how they walk as well.

You gotta keep your phone on and leave it at home that way it will look less suspicious