Yes, come back in a join in the fun!
In a way I have multiple tracks because we have the various generations. If I go back to previous a generation, I can remove a part with cut and paste. If I want to pan a part, I can duplicate the track and reverse the left and right channels. With the original and the flipped track combined, everything is centered. From there, I can slide things around a little bit. It's not perfect and certainly not as clean as working with the original tracks and a single project file, but it serves the purpose down here.
Dropbox does let us share a folder, so a project originator could share a single Dropbox project and everyone could work with it in Dropbox from their own computers. But all participants would have to use Audacity and Dropbox. We may do a few like that, but it's better to have as many players as possible, even if the quality of the final product suffers. It's all for fun anyway.