I would add a few things to the list, but of course they are based on my needs and wants.
-Expansion capability:
I don't know if I will need a parachute or floodlight, etc. etc. but ut is good to know these and others are possibiliyites
-Upgrade capability:
4K is coming, which means I will need to shoot at hignber resolution and down render to 4k. I don't want to have to buy a new drone to do that. HERO 5 (with 8K) is out in December.
-Mod capability:
This is a bit realted to 'open sorce" but not entirely. I am not huge on mdding, but many people have swapped GPS units, WiFi cards, Cameras, etc. etc as well as numerous configuration tweaks to get Solo to do their specific bidding. I like the idea that these things can be done, and are generally supported by 3DR (though they may void warranty). This opens up possibilities in many areas i.e Infrared mapping, etc. etc.
-Wireless tablet capability:
it is frustrating to me to have to use USB cables to connect things like tabets and controllers
-Wireless updates:
It is equally frustrating to have to connect USB cables and or put files on SD cards to update device/gimbal/controller.