KSP has developed their own custom format to store their game ressources afaik. They don't rely on Unity for that as CiM2 does.
But KSP is indeed worth looking at as for how to successfully combine Unity&Modding. Not just for allowing user made models but also usermade plugins to modify/extend the gameplay/UI.
But KSP is indeed worth looking at as for how to successfully combine Unity&Modding. Not just for allowing user made models but also usermade plugins to modify/extend the gameplay/UI.