If the open world NM drop U/U equipment then that would be ok wouldn't it? Why would anyone monopolize it if their whole group had the drop anyway.

If they had a decent drop rate, a reasonable respawn I don't see a problem.

I wouldn't mind a couple with crazy or random respawns depending on the drop. It is fun to run into something rare and go kill it. However I agree it is not fun to lose claim after claim to another group.

It's a pickle, I don't like a ton of instanced stuff either. A dungeon they intend a group of 8 to run, fine but I would miss those nights where I'm exploring or looking for a NM and bump into someone new and make a friend. I like to hear "Hey, can you help me?" and be able to give them a hand and if everything is instanced we lose that.