I'm out too!
I know it was the cubes that did for me and the 2nd and 3rd cube formations at that. I'll try again next year.
The best of luck to everyone still in. I was disappointed going out at stage 1 so I imagine going out at Stage 3 can be heartbreaking so make sure you prepare as well as you possibly can, don't come out thinking you could have done just one thing more to prepare.