You can use a simple Y and no reverseing gadget is ever needed.

When you have split and independant elevators and the two protruding elevator servos out the right and left sides of the fuselage simply attach the push rods at the servos on opposite sides. One pushrod clips to the servo output arm on the Top side and the pushrod on the opposite side clips to the servo output arm on the bottom side.

Simple, no need for expensive gadgets, no reversed servos, trim functions as advertized and no disadvantages. Simple geometry.

John