An additional button would make the colony manager more complicated and crowded. Also, adding a feature requires dev time and work. That button you suggest would be used ony by a part of all players, and is only useful in certain situations (late game, very good economy). Basically, it´s not worth the effort.
What exactly is the problem, gameplay-wise, you would like to have fixed? And what would be the easiest, most convenient way to fix it?
