My suggestion is a bonus interface which allows to see in one glance what kind of planets are in a colonized system while showing the improvements.



I got the idea when i played a round with a lot of arctic and desert planets in my empire. I wanted everyone to be happy and used the system upgrade infinte supermarket (or something like that) but since i had a whole bunch of systems it was very easy to lose track where the improvement has already been installed or where it would be the most usefull.



As always please ignore if the suggestion has already been made but I couldn't find anything with the search option.