You use a couple of different terms that make it unclear exactly what the problem you're having is. You say it "crabs as much as it did without a gyro" and also that you wanted it to correct for adverse yaw.

The amount of yaw required to keep the plane traveling a straight path over the ground (down the runway) will never vary because of the use of a gyro. The tendency of the plane to turn the nose into the wind, WILL be greatly improved by a gyro. If you are noticing that the plane still wants to turn into the wind with the gyro enabled, I suspect that your gain is too low or you don't have enough rudder travel.
While the Cortex won't eliminate the tendency to yaw into the wind it WILL, once setup correctly, dramatically slow it down to the point where only a small correction here and there is needed to keep the plane pointing down the runway. You still need to point the nose in the correct direction to keep the plane traveling the correct path over the ground and then straighten it out just before touchdown.