Idk but I'm gonna try it
Edit: Ok I'm not sure what happened, but this is what I did: I exported my data. downloaded another copy of Mindustry, tried to import the data, got a couple errors, checked Campaign, and somehow I have all of my data in the new copy. not sure if it was me trying to put the data in that made it work, or if Mindustry keeps data across multiple copies. But regardless, it worked!