Hi,
Though it’d be nice, it’s technically difficult – because under the hood it would mean unzipping them all, and re-zipping them into one… and theoretically, there could be any amount of data in there. However, it’s not necessary to download anything when cloning your site – a quicker method is to set up your destination site to use the same storage as the source site (e.g. same Dropbox) – and then after saving the storage settings, press the “Rescan remote storage” link in the ‘Existing Backups’ tab – then it’ll detect the backups, and do the downloading for you when you hit the ‘Restore’ button.
David