Domed cities being a prerequisite for agrav fields make little sense in case of gas giants. Aren't these colonies just orbital habitats in the first place? Then the gravity there should have been artificial anyways, since things in orbit are weightless since they're always in free fall. In that case, high gravity shouldn't affect any gas giants in the first place
My understanding is that gas giant colonies are floating in the clouds, not in orbit.
In either case, that should function as domed cities, right? Also, I don't exactly agree with the defense malus to domed cities because you want to avoid homogeneity of planets. 12 structure limit means we can't build everything everywhere anyways, especially since no atmosphere, habitable, non-habitable and gas giants all use different types of colony items anyways. I'm not building Mesozoic park and Gene lab in a barren planet with no atmosphere because I want fuel and refinery there instead. Realistically my farming worlds won't have mining unless I need organics. As for Domed Cities, if a Terran planet doesn't have high/low gravity, there's little reason to build them right? I could just change the climate!
I don't view gas giant colonies as being any more centralized than a regular colony.
I've discussed the Domed Cities defense malus at length several times in this thread. I'm not going to remove the defense malus, but I might add a settings option to disable it given how many players are against it.
IMO the dome would make the defenses even stronger, but perhaps make it more susceptible to bombardment because the cities are more centralized. But I'm alright with it either way, that's not my main concern.
I'm thinking more about the nature of colonies on gas giants and agrav cities. You don't think these are huge centralized habitats, so are they little floating neighborhoods like in Bioshock Infinite? Or are the people scattered around like floating houses from the movie "Up" lol. All of them would require some sort of atmosphere sealing, right? If people in Terran planets can be gathered together to form domed cities, why isn't the same possible for gas giants? It should be feasible at least bring enough people together to form the equivalent of a spaceship, at least.