Few months ago i made a Gauntlet mod for BO2 Origins, Gauntlet is a Black Ops 4 gamemod where the goal is to speedrun 30 rounds with different challenges or restrictions on each round.
Instructions and download are available on GitHub. The release is marked as beta but i consider it done at this stage, really happy with how it plays right now.
It's been tested for solo and coop up to 4 players, with mainly speedrunning in mind. Not planning on doing other maps at the moment, but i'm not ruling it out completely for the future.