This is correct. DJI uses a Catmul-Rom spline to define the flight path from the waypoints.
Speed has nothing to do with the path. Geometry alone defines the path.
Birds that whine like small drones? The exact same noise from the small quadcopter drones I saw a few minutes earlier at a lower altitude? Same noise, just a few hundred feet higher? I’m not an idiot, I’m not asking if they’re birds or not, I...