About gravity: there is an FLHook device that helps simulate gravity quite easily. So that's not an issue.
What is an issue however is the immense amount of workload required to make this work. Not to mention testing and modelling. I guess the modelling part is the biggest obstacle, none of our modellers really even tackled making bases yet, let alone whole systems that involve custom models for everything inside. So this is perchance the only reason why this isn't happening. I'm sure it could, but it's just out of our league at the moment. The modding team is busy trying to finish up all the other aspects of the mod, as well as push the story forward.
Of course, if anyone else wants to give it a shot, feel free.