On balance I think there's a case to be made for outlawing this. It's only of relevance for the first few targets and if the next lane is at a skewed angle to the last it's doubtful what benefit you'll gain from seeing the wind deflection.
At the same time it brings issues of which target was shot, the order in which they were shot, and the buddy has to be fully attentive (which if you see the slack timing on some lanes
) isn't always the case.
If it's banned elsewhere then others too have concerns.