Exporting custom map data : not exactly a must, but since community maps tab feature is not yet a thing, this could be added to help users share maps or collaborate map creation. (of course to validly open a map data file you need enough tiles or else you may just view or be denied of opening the map data file) and of course this can be useful to backup maps for any reason incase someone a user has not registered or lost access to their account unexpectedly.

Displaying total amount of each tile used : this is pretty self explanatory, displaying the total amount of used tiles can help a user identify their map work and possibly help in calculating in what the map sell income is gonna be, and in general its not a bad thing to see your tile usage once in a while.