>>714677457>semi-open hub world into semi-open worldsThat don't make sense.
Putting gates into your semi-open map to reach somewhere else make it a hub.
If those gate link to each other, then it's a semi-open map with fast-travel point.
Arguably that make the average Bethesda game a hub. Starfield procedurally generating map or not.
>>714692961Joke aside, and ignoring the simply making those underground levels, it would be creative to have superposed overworld as "distinct plane of existence", where you are spatially at the same place, but don't interact with the other plane the same way.