This would be awesome. It would be really handy to be able to export all of my subscribed communities as part of a boost backup so that I can recreate my account if my instance ever becomes not-available or I need to move to a new instance for some other reason.
If Boost were able to take a snapshot from one account and import it on another it would be pretty easy to maintain a "backup account" on another instance that I could use whenever .world is down for maintenance too.