Thesis Restore Points allows to you create and restore multiple backups of your Thesis (or a Thesis child theme)'s custom folder.
The backups are stored in
your-uploads-folder/thesis-restore-points/filename.zip, where filename is a random string.
A blank index.html is created by the plugin, to prevent directory listing of the folder.
If you'd like to change the location of the saved backups, you'll have to edit the plugin. I hope to add a better way
to do this in the future.