I don't know how planning can be of effective help here. The point of the inner boundary is to give a safety margin that takes kinematics into account, which under the effect of the wind is a non-modeled perturbation. In a world of vehicles that can go from hover to 100km/hr, there's simply no way to plan the mission such that you can make guarantees about where the safety boundary will be in meters. 

There's no possibility of a false positive in the safety zone without a false positive on the boundary. The safety zone is designed to be the point at which the model takes control and returns itself to some safe position. The user ideally would configure the vehicle to autonomously veer away from the real boundary. After crossing the geofence it's too late, the regulations stipulate a crash.