Yep. The total number of hurry ups determines what happens when you finish the last one.
1 or 2 hurry ups: nothing
3 hurry ups: Advance Itchy (open targets or count lock … can’t remember if either of these is willing to start the multiball, but I think they are)
4 hurry ups: Advance Couch (score 1 lock)
5 hurry ups: Light EB
6 hurry ups: Light Special