I'm going to put all the new functions of this update and how to use them, as we go finding them and discovering how they work.
- Support for return to controller
Under options, Safety tab, Return Home Settings section. You can set it to return to the takeoff point or to go to the ST16S or GCS (Ground Control Station) position.
- E90 digital zoom up to 8x
In an area without controls, where we see the image of the camera of the E90 in the ST16S, pinch two fingers on the screen.
- Support for terrain following
When we create a mission we can make the H520 follow the terrain, a very useful function. We only have to activate the option Vehicle follows terrain. You can set the security altitude range and the maximum ascent and descent speed. Very good function. Thank you very much Yuneec, well done 



(Enabling this option disables the possibility of making a cross grid).
Support for concave polygon missions
Yaw stick deadzone and exponential curve
Brake at waypoint in mission if stop is required
Vehicle can stuck in a waypoint during mission
Fixed altitude lock during mission
- POI/ROI support
Region of Interest (ROI) allows the user to set a point of interest, for which the camera will stay focused. We establish the ROI and the height at which it is found. We can establish the height with respect to the Home, AMSL or AGL. This way of setting the height also applies to Waypoints making them now 3D Waypoints.
- Orbit flight
Take off, open the map view, tap on the map where you want your POI. A pop up opens asking if you want to fly to that point or orbit that point. A circle appears that you can change the size of and you can reposition the POI. When your happy you have to swipe the screen to confirm and the h520 flies to the edge of the circle and starts the POI. You can change speed and direction using the Aileron stick and decrease the size of the circle using the elevator stick. You cannot increase the size of the circle beyond the size you created on the map. You have to edit that on the map page. Once the POI has started you can go to the normal camera view page and also adjust camera angle.
I've noticed that satellite reception has improved. In the same position as always and when before I did not receive enough signal, now I receive signal from time to time and it remains stable at times. I don't know if it's because of the time of year, it will be a matter of observing it more times.
It has happened to me 2 times, changing the configuration of the camera, the parameters of photo and video, the application has crashed. DataPilot is restarted and re-establishes the connection with the H520.
When we add a new set of offline maps, another one is created with the surname "Elevation". I think it's a way to save the elevations that are going to be used with the terrain following function separately.
I don't know if it has changed in this version, but when you lose communication with the H520 or simply turn it off, the ST16S doesn't connect to the wifi data network you usually connect to. Previously it did it automatically. If we look more closely, the two wifi networks, the data and the E90 are set to Disable, which forces you to deactivate the wifi and re-activate it so it can connect to the data again.
When we create missions we can make them round or polygonal. We have added the option to eliminate vertices in the contextual menu. We can also load missions previously created in KML or SHaPe files.
Creating missions, on the Center button we have more options. We can focus the view on the mission we are creating, on all the elements we have created, on the home page, on the H520, on the current position of the ST16S or on a specific location for which we will have to set the coordinates.
Creating missions, in the button Plan we can save Waypoints routes as KML. We have also added the button to delete the mission stored in the H520.
When we modify a mission, two options have been added that will greatly reduce the creation time. Now to choose the point of entry and exit of the mission we have a button that rotates by all the external points, much faster and visual that to select it in a drop-down list. Also, and this I liked very much because I insisted on asking for its complementation, is that now to determine the orientation or angle of the Trancests, can be done with a slider. This will save a lot of time in determining the correct orientation and thus save mission time. Thank you very much Yuneec, well done



Morning's entertaining, but this isn't over. Still more things to discover. I've crossed out the options that I have not yet discovered or need to pay more attention to. Any contribution about them will be welcome.
If you see that I have put something wrong, please comment.
When I have some time, I will add everything to the first post.
After resetting the E90 again with the latest firmware, I've already restarted the H520 about 10 times and it still seems to work properly.