They could take what they have for the Masked Carnivale, but make it low man content, and fill in vacant slots with Squadron/Trusts

Like the Colosseum from FF7/FF7R where it's basically floors of mini boss fights until the main boss. So you have that option to run with friends or with Ai. If they really wanted to, they could add a "Chaos" mode where you could get gear that rivals Savage in item level once a week, but the challenge would be ramped up.

They did showcase for the Bozja content you can go 1v1 in a Savage/Ultimate style fight against a large enemy... could be a testing ground for content by seeing how well it's received.