The clean install of 360 MD will not wipe out your local vault as long as you just start the installer over your current version.
It may remove your current version, but as long as you watch the prompts and maintain settings, your local vault should be safe.
After you get the new version registered and activated, be sure you watch any prompts when you go to sign into the ID Safe vault. Be sure you do not accept any offers to convert or merge your vault to the cloud.