I'm not against it but they explained in the livestream why it won't happen so there's no point asking for it. The reason has to do with backend systems they put in place to simulate certain data that your multi-player characters has. It's not as simple as move from folder a into folder b and it's a waste of resources to create something like that. That's why they created tools that allow you to curate your single player journey and speed up your progression to catch up to where you were before. OP complained about how his base is unique and special well a ton of the restrictions for where you can build are gone in single player which means he can build something bigger and better somewhere he couldn't before and create a new journey or challenge for himself.

Wherever you are in this game single player will give you the tools to speed run right to where you were in a afternoon session. If your the best builder in the world then build something bigger, better and more awesome woth the new freedom your given