I really like the Trip overview. It helps in checking if the flights fit. And it already can use the remaining the fuel for the next flight. My suggestions for making it even more useful.- Optionally hide (with checkbox or collapse triangle) all intermediate points of the flights. So only show takeoff and landing point.
( I do like the sunrise and sunset indications, very thoughtful)
- Allow the takeoff times to be edited. Show the time on the ground in a simplified way (e.g. 1:35 or 1d; if more than 1 day difference you are not planning the flights to fit in sequence, so exact time is not relevant).