I have no idea how the Ackerman effect ( more travel in 1 direction than the other ) can take place if you do a Zero Setup with the servo horn at a 90 degree angle to the fuselage centerline & tail control horns also at a 90 degree angle to the fuselage centerline.

Equals always give equals.

If you do not set the transmitter computer to 0 offsets or the trim levers to 0 then you can build in a offset. True. some servo arms will not give a 90 degree angle to the centerline. Cure is to make a VERY THIN wood wedge to get it perfect. Is that being too fussy ? Maybe. But none of my planes fly with any trims. Computer or trim lever. I can hit DEFAULT all day & no plane changes trim.


Edit. I do have 1 plane, the Martin China Clipper that DOES have a built in Ackerman Effect do to a VERY HIGH elevator. Still did a Zero Setup for equal throws.