When deploying Echo at es.Wikipedia, Fremen asked if Echo could be used to follow pages beyond those you created, like the watchlist does. I thought that this was a bit unmanageable until he explained in detail what he was referring to. What he suggests is that Echo can be used to follow certain edits rather than all edits. He gave the example of Echo notifying a user when someone removed a category from a page off their watchlist, and I can also think of more examples, like when a page on your watchlist is moved, or deleted, or restored, or a revision within any of these pages is revision deleted.
Such enhancements will make Echo an even more powerful tool than what it is now, and will expand its usefulness by a broad margin. We can also explore, in the future, the possibility to make Echo to report users when a page off their watchlist received a maintenance tag, et cetera, but since these tags depend on templates that vary throughout the different wikis, that would be time consuming and may not be very useful (we still have the watchlist though). Any thoughts?