As I expected, when you call osSetWindParam from anywhere in a mega region, it sets the wind for the whole mega region. This means you can only have one config wind setter for your whole world. Well, you can have as many as you want but whichever one you use last, it will over-ride all the others. This means there is still room in the worlds for a scripted wind setter. I wrote my sailboats to listen to the closest one, so you can set out several scripted wind setters with different conditions around the course of a race. And I also have the option in the dialog for the sailboats to listen to the SIM wind instead. The race officials could change the configurable wind during the course of a race.
When you call osSetWindParam, it changes the values returned by llWind, it changes the direction that wind-enabled flexies (flags) bend, and it is supposed to set the direction that wind enabled particles move. That last thing works in the SW sub-region of a mega region, but particles in other sub-regions do not follow the set wind! If you release particles in the SW sub-region, and blow then into another region, as they cross the border they will slow down and turn to some default wind that is always blowing from the SE and very gently.
This isn't a big problem, scripts that use llWind can use the SIM wind, flags and pendants will turn the right direction. I will probably release my Configurable Wind Setter with things as they are.