I sat my stage 2 a few days ago. As people have been saying, there is really nothing you can do to prepare for these tests other than read the booklet they give you in advance.
For the knowledge test I would also suggest brushing up on basic maths calculations for speed/distance/time. It isn't difficult though and there really is no excuse to fail this part. FEAST 1 is also not overly difficult if you have the required skills. You cannot teach yourself these and it is best to go in blind.
I reached the DART stage and I'm awaiting the results from that. I had one collision, 2 conflicts and 1 missed checkpoint though so I'm not hopeful, even though the final marked part of that I found the easiest, just took a little bit to get into the swing of things.
Good luck to everyone wherever they are in the process!