Curated drops are not working for dungeons where you loot the final bosses' loot from a chest. For example, in Imperial City Prison after killing the Lord Warden you don't loot your reward from his corpse, but rather a chest. I just finished a run and was missing the heavy monster helm and tons of weapons. So I should have at least gotten a heavy helm.
Instead I got a light helm, which I already had collected, as well as a weapon I already had collected.
The treasure chest seems to be the only factor that is different since curated drops has worked for all the other dungeon bosses I have encountered thus far. I know normal treasure chests are not curated, but they need to move the final boss treasure chests to act the same as the corpse of the final boss rather than the treasure chest loot table.