The next step is another length of bungy; the book mentions 3 lengths of 6mm, so I'd hoped that 9mm would be sufficient, but I guess not. We still have to be careful how we handle the sail during a shunt. It's easy to spend too much time getting tangled and not notice the boat spinning into the wind. It's too easy to be standing on the mainsheet, or the wrong side of the tack line and end up in a mess.
Here's another short video of us sailing: https://youtu.be/1nqyQFIQIgI
Meanwhile, I've started building the middle section. It feels much faster than the bow sections. Maybe I'm getting better, maybe it's easier or maybe it's because there's only one of them...