i'll definitely throw some stars at this when i get home.
this is a great feature, both for people like me who dislike most of the newer maps and would like to filter and play mostly older ones. and for people who can't stand playing older maps and only want to play more recent ones. it would benefit everyone and i don't think it would be too difficult to add in, though i'm not entirely sure what the implementation would be like. i know that the map's last updated date is already in the game through osu!direct, which should be a good enough sort filter for ranked maps.