Thanks to that double stamina bug i have now cleared all but the 3rd map. Going with two hyperspeed teams to make a whole roundabout on the thingie and kill the mobs i had to skip earlier.
And then i guess it's farming the 120 stage until the end of the event or something.
Edit:
Guess i cleared that map too. One megaspeed team running the whole map over after helping triggering the locked tile. A fast helper that runs through the middle, two super weak teams that only help triggering the locked tile and switch its direction, then a 4th team that is good enough to kill the pests but not the boss.