Well yes and no...
I have taught two dogs to "do flyball" for fun - my GSD and a BC that came to the daycare I used to work at. I have never had a dog compete in Flyball or be on a team. My GSD did well enough at it that when I went was at a Pet Expo and took her to a Flyball demo/"try it with your dog", the team that was there asked me what team we were on. They were surprised that I had just taught her to do it on my own and that there was no Flyball in my area.
This is a Flyball class run by a local team that started up a few years ago. So this is the first I have gone to actual Flyball classes with the idea of training a dog to compete in it. We have not introduced the box yet but have started on box turns, as seen in the end of the video. This team likes to break everything into smaller parts, so the dogs can master each skill before putting them together. I think that's probably the best way to go about it. Most ball driven dogs figure the box out very quickly but if you want them to do a "swimmer's turn", you need to train the turn before introducing the loaded box.
I used to joke with the BC that if I could train her to reload the box, she would keep herself busy all day LOL.