the idea is for a window from which the user can launch projects and "multi-projects"
multi-projects open multiple projects in tabs.
an action to "save all tabs to new multi-project" would be required.
if you have a project open, opening the manager window would display three kinds of files organized in seperate columns or folders: previous (or later) versions, backups, and associated multi-projects.
you could also navigate to other projects and view their associated versions, backups, and multi-projects.
this feature could be integrated into the kind of project manager described here:
http://forum.cockos.com/project.php?issueid=155 . this could be quite powerful if you could view for example audio files associated with different rpps for import etc etc.