It seems that doing the Unlucky title just opening chest is now proportional to the number of opened chests, wherever they are encountered in the game.
Opening chests of the begining (ascalon, shing jea, istan) would be the cheapest way to achieve the title because more Unlucky points / lockpick breaks. However the best way if going for treasure hunter title would be to open only 600 gold chests.
Still need confirmation of those numbers