If you'll allow me Tom, I'm going to give my opinion.
The drone's ability to use terrain data such as SRTM would be a very interesting option. Normally and looking a little bit at the accuracy SRTM gives (from other sources the same thing happens) they themselves tell you the average error it can give and I think I remember that it is over 20m if I am not confused. With this information and to avoid problems it is recommended to fly over 60 AGL as a safety measure. This recommendation is made when using the Px4 past flight scheduling systems that already have this option.
If apart from that we have an altitude detection system, Intel Realsense most likely would greatly improve the accuracy and safety of the flight. When they made the presentation of the H520 in France in an interview, a manager commented that later on other models would come out and would incorporate it. We don't have confirmation yet but I think they will implement it as it happened with the H480.
With regard to incorporating the possibility of an anchorage for the gymbal at the top would be something very nice and would give more versatility. The idea is good but there are many problems with gimbals performance when installed in top position. I think they're products that play in different leagues. Carrying two cameras means increasing the weight, decreasing the flight time and making the aircraft rise above 2 kg so that in many countries and according to regulations BVLOS flights could no longer be made.
Having available batteries of $180 with an autonomy of 40 minutes for a certain aircraft does not mean anything. Each aircraft is focused on something and designed to do that function. I'm not saying anything about the H520 batteries because I think they're expensive too, but let's not confuse 4- or 6-motor multirotors (if I'm not mistaken) because they're different worlds. I use 6s and 12A batteries and get 35 minutes but I don't have any other virtues that the H520 has, all in its right measure. By the way, can you say what battery and drone are you talking about specifically to compare? You've left me with the doubt and having other points of view is always interesting.
At the fair I was talking to some nice guys who had designed a quadcopter with LioN battery and 55 minutes autonomy. The engines and propellers price were of the other league where the H520 dont plays. I didn't even want to ask the price of the set because I'm sure it wouldn't interest me. There's a lot better things out there, but you have to pay for them. I say this because price is often a fundamental factor when it comes to starting to look at drones, among other things of course.
Finally and making it clear that I am not trying to argue or offend anyone. I've been looking for a long time to buy a good drone for making videos and images, specifically for the image theme. I don't think that the H520 is a bad choice considering the path Yuneec has chosen to continue taking into account the advantages of being able to do photogrammetry.
I think that over time the functionalities of the aircraft will increase but we don't know anything for sure yet. This is a problem for people who want or need to buy it now but this will always happen to us. You're gonna buy something, and there's always something better about to come out. In the end you have to make up your mind, otherwise you'll never buy anything.