I've heard complaints about wind at contests, especially at BAC...
Here's the thing.. I find that yoyo freestyles are in a sense no different than professional baseball, tennis, football, skateboarding, or any other pro sport/competition.

You practice practice practice, then the day you need to perform god throws natural elements at you.
You need to adapt and learn to deal with it. Pro skateboarders don't complain about sun in their eyes when they're going up a ramp at high noon, tennis players don't complain about a little drizzle, football players don't complain about playing in the snow.
You just do your best, you're in the same position as everybody else at the contest.