Yes, even with no waypoint in the SDK, implementing a waypoint with virtual joystick would be a piece of cake for a good developer. It's as simple as implementing a close loop between commands (Joystick) and measurements (GPS position)...As @RogerDH mentioned, Dronelink may be the solution to this. This from the Dronelink support site: Upgrade to DJI Mobile SDK 4.13 (with Mavic Mini support). The mission (with waypoints) is stored in the app rather than the drone and apparently works by sending commands to the drone in flight. This could be a game changer for the Mini.