IMO I would reward him for running through the poles even if you didn't say go - like Dekka said, rewarding the free thinking. It can be a PITA to have a dog doing exercises even when you didn't tell him "go do that," but it's so early in the game I would reward drive and worry more about the self-control later. I think the easiest thing to do is not say anything at all, no cue words, that way you're not tempted to only reward when he performs on command. If he offers the behaviour, if he wants to do it (and he totally looks like he wants to do it!), reward and celebrate!
The one downside to 2x2 that I have noticed while watching YouTube videos is that timing with the reward needs to be spot on and it's hard for some people to get it right. You don't want him turning back to look for you to throw the toy. He's mostly just headchecking you rather than turning his whole body back, but he should be just looking forward and continuing to drive ahead. Launch his toy just a second faster and that should eliminate the headcheck. Like as his head is going through the poles, so goes the toy. Not that Finn really needs a lot of help with drive, LOL, but if a dog gets in the habit of headchecking, constantly looking back and going "what now Mom??", it will likely result in dropped bars - especially with a larger dog where his hind end could come down as he's twisting to look at you.
I've only got Shaping Success and I hear she updated some stuff in the DVD, but it's so darn expensive that I just haven't talked myself into buying it. I've been just reading the book (like a million times... it seems simple but then I keep being like "wait, what?") and what I can pick up from watching videos of other people training on YouTube. There's a bunch of people who have taped pretty much their whole training process. And the best part about watching other folks on YouTube is you get to learn from their mistakes, which is always good, LOL.
