That Black Hawk mixing unit is a work of genius.
Its been a while for me, do you remember if the stab also has a yaw rate input?
Yes, I think that was part of the lateral accelerometer input you mentioned earlier. From memory, the lateral input to the stab was one of the most significant, although I dont remember the reason being the one Jack C gives above (cantered tail rotor). I recall the need for all that authority was that the stabilator itself changed relative airflows with sideslip. In forward flight, pushing left pedal caused the stab to move out from the downwash influence and would cause more lift, therefore a significant pitching moment unless the stabilator moved. Right pedal caused the opposite by moving the stab further into the downwash influence and losing lift, also causing a significant pitch moment if not countered by automatic stab movement.