And if we’re just pontificating for our own amusement, I am actually not sure where hard-coded difficulty increases would go in the framework of a single play-through of Grim Dawn, because after beating the Warden in Act 1, you can just hop directly into all of Forgotten Gods if you wanted before ever heading northwest out of Devil’s Crossing. Fangs of Asterkarn is reported to start at Fort Ikon:
So it’s not clear where Elite and Ultimate would trigger, especially for people that never want to play Ultimate at all and like the difficulty of Normal or Veteran just fine.
And it would definitely require some multiplayer rework since characters currently can’t join games hosted in difficulties they haven’t unlocked.
It would also deprive people of the joy of doing Act 1 in Ultimate on a Level 1 character.