Gybing daggerboards just require less leeway angle (relative to the hull) to produce side force, because they are setup with an angle of attack relative to the hull.

I'm dubious about gybing boards on cats because the leeward hull provides a significant side force when at a leeway angle. If you try to reduce the leeway angle, the boards have to produce relatively more of the required side force, probably requiring more board area, which I'm not sure is efficient.