BA was sending one out to teams in advance of u14 Club Champs a few years ago, not sure if they're still doing this.
It's a really, really hard rule to enforce, though. It's rare to see good teams playing zone in a competition where it's banned, so a lot of the time it's a result of a kid who is lazy or lacks understanding.
It's worth keeping in mind that a team playing a banned defence is simply not going to develop good basketball players. They might win a game, or even a lot of games, but they are doing it by making offences play against something they are completely unprepared to tackle. There is no learning opportunity there for the zoning team, so they have a vastly overstated sense of their own ability, and eventually will be shown up for not having learned important skills that everyone else was figuring out while they were busy worrying about coming 3rd instead of 4th in u14 div 3.
I see a lot of parents, coaches and even players get very upset when they think the other team is in a zone, even when it really doesn't matter. The margin might be 30 or 40 points, they might be up or down, and they're still trying to drag court supervisors over to get a no zone rule enforced. Just play to the best of your abilities and don't waste your time. Pick up the pace and get the ball down the floor before a zone gets set - an u12/14 team expecting to run back and stand in the key will be rubbish in d-trans because they have no idea who is responsible for lane runners because that has nothing to do with the zone. Rebound the hell out of it because boxing out from a zone is hard. Play good defence and force turnovers to create advantage situations rather than letting them play half court 5v5. So many better solutions than worrying about the other team's zone.