Saving and creating new versions should be changed and separated. I think current solution when you save design and Fusion will automatically create a new version isn't good since versions are useful tool to go back and do revisions. Current behaviour will cause a lot of versions over small changes (or no changes at all if you for example click "Edit Sketch" and exit it without doing anything and then save) which is not useful.
What I would propose is the system where you save a file and Fusion will ask you if you want to create a new version from it (add an option like "Save as a new version"). That way it will save changes to current version by default (Ctrl+S) and if you want you can create a new version (i.e. Ctrl+Shift+S), add description and then continue to work on it.