I just do not see this as a big deal. Most agencies with dash cams are on DVR, and always rolling anyhow. We all know the public has no clue what an arrow stick means. Why would you need to hit the air horn or siren if you are out side of the car? And are we supposed to walk around with the phone in our hand and the app up ready to tap the screen? Sorry, if I am on a traffic scene, I need my hands free to set flares, direct traffic, fill out wrecker sheets, or just scratch my rump while four out of five lanes are closed. As far as shutting lights off for HGN tests, the practice I've always seen has been to shut the front lights off after the suspect vehicle is stopped, turn on the take downs, and make sure the camera and mic are on. Outside of that, say patrol curbs a violator, and decides to HGN test, the LEO has returend to his squad to run the DL, and the suspect is still inside his vehicle. The front lights go off and then the testing starts. I just do not see it as a big seller, or really any kind of increase to Officer safety.
Try again Code 3.