Yep, the assets won’t be re-uploaded if they already exist. For worlds, it will ask for confirmation before overwriting, so you can just redo an import, it would add new assets or update any modified file, it will also ask if you want to overwrite each of the worlds it finds, so you could say no, no, no, yes, if you wanted to just overwrite one of them. Modules/systems would also get updated to match the versions you have locally, so you might need to redo an ‘update all’ after that.