A badly formulated idea, but inside a specific location, like a scavenger hunt, a portal or altar appears and run a solo dungeon of the location difficulty or monsters. completion could be like pqs with reduce amount of reward, since it'S a shorter quest.
A solo dungeon could be a race for a temporary high score for that mini-event.
I know the idea of solo dungeon is not really inside MO, but i think it's an idea we could explore!