Switching Projects

I really like MarginNote, but there is an area I’m struggling with. Searched the forum and can’t find anything that helps, apologies if I’ve missed something.

I need to be able to switch between completely unrelated projects, that don’t share any documents. I don’t want one project getting clogged-up with files from the other project. In other words I need to be able to switch, with a clean start, between the projects. I’ve tried doing it by recovering from backups, hoping that the ‘Replace’ option would do the trick, sadly the ‘Replace’ option merges the recovered project with the one I’m trying to replace. I’ve tried this on iPad and iPhone, I’ve not yet tried it on the desktop version.

Any help would be appreciated. Thank you.