side force generators are de-stabilizing directionally. The neat thing is that, with SF generators, you can destabilize the aircraft directionally without affecting the longitudinal stability. For example, you could increase rudder sensitivity, or make a plane knife edge better by sending the cg aft, but this would simultaniously result in poor longitudinal stability.

I am interested in why people are seeing better tracking. I find this hard to believe. A sideforce (crosswind) should have a tendency to blow the entire airplane off-track, instead of yawing the airplane and allowing it to crab, thus staying on track.