I think you need to use Litchi again. I used it for more than a 1000 flights with my Mavic 2 Pro's. They do not use virtual stick operations. Once the flight is uploaded you can switch off the RC and wait for the AC to come back and land nicely next to you. Once connection is lost though the gimbal pitch will NOT be adjusted anymore. That's what Mavic 3 Waypoints does indeed. Without that the video below would never have been possible with Litchi. The AC (M3) was already flying more than 10 minutes without connection and still gave the perfect pitch to the gimbal when arriving at the castle.You are seemingly uninformed re: Litchi, and the entire issue of on-board autonomous waypoints vs. "virtual stick" operation. Have you ever even used Litchi?
"gimbal [sic] pitch and direction of the camera is uploaded to the aircraft, so , even when the signal is lost for a short ( or longer) time the flight is exactly executed as planned" has nothing to do with Litchi or DJI Fly waypoints.
It's a function of the aircraft model.
W.r.t. autonomous waypoint operation, if the aircraft supports it, it works the same for Litchi as for Fly.