Duplicate of world for designing in creative mode?

Hey, I'm hosting a server for me and my friends, using fabric - latest version.
I'm looking for a way to have a duplicate of our regular world but in a creative mode, this way we wouldn't need to switch between our singleplayer saves in order to design new stuff that then we build in survival mode.

- server is hosted on oracle cloud
- preferably it should be possible to access the second world using some sort of a command and not by connecting to a second server
- the accessible region should be limited - let's say a region of 2000x2000 or less - can be specific chunks/regions only
- maybe a way for me to manually/automatically update the world to the latest one from the survival version.

Does anyone know a mod or something like that, to accomplish something like this? I've looked into Multiverse-Core but it doesn't fully work in a way that I would like - mostly it misses a way for me to update the creative world to the latest version of survival world.