Honestly a NM in a dungeon I do not even consider "a High level NM" that is a boss mob. Even current mobs I question if you can call then NMs due to their incredibly short spawn times.

Settlement boss NM was ok I guess. Sorta a boss mob there as well.

I want to see more random spawn High Level NMs, give me reason to go into X part of the world. So many void places that NMS could fill up. Make special conditions, make spawn items drop occasionally form random mobs. Bring use to 80% of the game's areas that no one ever goes to.