You can also seal the hinge gap lines. Beats me how much of a gap to have.
I''ve seen kedets with 1/4" gaps.lol

anyway, if you seal it you'll get more air flowing over the control surfaces.

I go with the moving in on the control surface side....only

If you move it out on the servo side, you''ll loose torque.... more throw,but no torque.

You can just mount two servos side by side at the center of the wing , if that's how your set up is.
Not that big of deal. No need to run extensions...cut into the wing and...etc
Just use a Y harness and you're done.

you can even couple the servos...when you see the set up...you'll laugh..it's pretty simple.