I get what you're going for but it's the same problem as with space elevators and mobility for ground units and bunch of other suggestions, in that it encroaches on the RP side of the game by providing detail that is actually unnecessary for game play purposes.
What's the difference between a space elevator and a level X space port in a game where such things only affect the loading and unloading speeds of ships? What's the difference between a walking tank and a tracked tank in a game that does not model more than 1 terrain type per planetary body nor any sort of tactical combat? What's the difference between researching Arcology tech and building Orbital Habitats in a game where both just add additional population capacity on a body?
The population densities that C# will allow are already pretty generous. Earth will have capacity for 12,000,000,000 people. That's a lot when you remember that it isn't just the physical space that all those bodies require - and you can't stack people like firewood - but also their jobs, their entertainment, their food production, their energy production, the entire trade goods sector and more.
If/when Aurora beings to model the civilian sector in more detail, including food and energy production and consumption, such techs will become useful additions.