Mini Dungeon Event

Movement skills (Haste, Teleport, FJ, etc) don't work in the minidungeons during the event. He's referring to BS's "movement", even though it really doesn't move you at all.

I'm kinda wondering whether or not Assaulter works in there though.

The problem with boomerang step is not the appeared movement, it's the period of invincibility you get. In a real jump quest, you could exploit this to dodge a fast obstacle. It's really just a ranged attack that makes you invincible during its duration.