BTW, full deflection is what caused this mess in the first place.

And you're not going to lose total deflection because with the rigging change proposed, the up deflection is being increased quite a bit, more than the down deflection is being decreased.

With the rigging changes, you get roughly the same total deflection, only it's balanced to the needs of the aircraft, not just slapped on the sucker. There is nothing magic about 50% up with 50% down. But there is magic in getting equal lift and equal drag. What you get is a change in the roll axis that doesn't affect the yaw or pitch axis. Balance the aerodynamic results to the desired needs.

You're not just reducing the down deflection. You're increasing the up quite a bit and best of all, you're reducing not just the down deflection, but the wasted excess of lift and drag on one side.