I think that could be fun. I think objectives like this are interesting ways to build on the existing game.
Although first I’d like to add a Single Self Found leader board online.
I’d also like to improve the Terror Zones first, buffing the Super Unique monsters and adding Guest monsters, and then making it so you can try and clear all Terror Zones in a single game (with a small reward if you do).
I feel like once those things are done it might be worth adding something like a defend the objective challenge mode.