Getting Pit/Upgrade materials from NM dungeons feels weird (although its much better and faster than previous seasons). I feel like Blizz is/was struggling to find a place and purpose for this activity and tossed what used to be pit materials in there and it feels odd.
Suggestion: put obducite into HT or back into Pit or someplace else.
Re-work NM dungeons to the following:
Open up the world map and the available NM dungeons you can run are brilliantly high-lighted (based on what sigils you have). Click on one of them, and fly-in list of affixes to apply comes in from the left hand side of the screen. Tons of affixes to choose from (ex. % increases to monster density, rarity, damage, life, multiple butcher spawns, hellborn spawns, monsters have % resistance to XYZ element/damage type, player resistances are lowered, player max hp and shield lowered, etc etc you get the point.
Player can select any and as much as he or she wants to increase the reward. The affix shards for these affix that we can apply to NM dungeons would be found and picked up in a similar fashion to gold(just run over them), and the dungeon drops a lot of them. Allow us to really juice up these maps for nutty rewards but at the cost of very tough mobs.
Sounds like POE atlas or LE monoliths, and that would be correct. Those systems are amazing ground-level base endgame systems that give the player a ton of agency over the type and difficulty of content, for whatever reward they want.