Paul Farquhar
Legend
I don't really see any reason players would touch unnumbered buildings. For one, they look anonymous on the map. All the numbered buildings have a distinctive appearance. And then there is Augury, which can be cast as a ritual in 11 minutes and determine if a building is worth exploring or not. Not to mention all the hints and clues that are to be found around the city itself. I guess as DM I could rig things to encourage the players to waste time on unnumbered buildings, but I don't see any advantage to doing that. They would just get bored. And my players won't be interested in any loot or lore that doesn't directly pertain to reaching the Mythallar.