Separate Buildings Category for 'Unfavorited' Improvements

Whenever I have the courage (and the time) to play a day-long game session and find myself in the late-game I always get this overwhelming feeling that the System Production window simply gets overcrowded and chaotic. More so, at this point, I already own a tad load of systems and I'm not speaking of the ones coming in due to military conquest or influence. Needless to say, it becomes a second nature to just queue up a system improvement after another, even if it doesn't necessarily 'make sense'.

To remedy this and maybe make things tidier, I'd propose a third category in the system production window where the player could drag and drop improvements that he/she would not consider (but still could re-consider doing later) for each given system. Take the example of a star system which by default doesn't have any sterile planets. Wouldn't it be reassuring to get rid of the improvements concerning these planets?