Make Auric Maelstrom a ballcruncher with a massive pool of potential modifiers, have it be the highest difficulty where a coordinated, yoked up group of SWEATLORD SUPREME types is REQUIRED to win.
If all the modifiers Fatshark has randomly discarded after events were used, it’d be impossible for any but the people treating this game as a job to get fully experienced with all of them faster than Fatshark could add new ones to said modifier pool.
Ultrasweats get their difficulty, casuals are gatekept out of it.
Also never have achievements or cosmetic rewards linked to the highest difficulty. That just creates entitlement among people who want the shiny things and cheese it.