Why did `MAV_TYPE_GCS` got removed? It means we'll accept heartbeats from other drones as telemetry status. I think we should limit to what we accept to our sysid or a GCS.  Something like:  ```suggestion  \t\tif ((msg->sysid != mavlink_system.sysid && hb.type == MAV_TYPE_GCS) || (msg->sysid == mavlink_system.sysid && hb.type == MAV_TYPE_ONBOARD_CONTROLLER)) {  ```