So you have a colony size 6, great farms or with a fuel production and you don't use all that poop being generated.
I know it sounds strange but even in the days of today great nations use this resource to help maintain themselves.
There should be industries that convert poop into compost, fuel or energy (I know the latter is not a feature in the game).
Increasing the productivity of planets with large populations.
And planets should have the ability to specialize in something even if they're good at a lot of things.
For example a planet with good farms and good ores, the player should be able to choose one (with the choice of a building) and get more resources from one than the other) without the need to have rare equipment (of course with less production capacity, than with one of these items, eg soil nanites).
Well these are just ideas, great game with great potential, thanks for your time.