I can't change the pushrod angles as its an ARTF and the guide tubes are already in.

Just a thought, I haven't set any specific end points yet, they are still at 100 % so there is a lot of throw. The two elevator surfaces seem to go out of alignment towards the top of the movement so maybe with correct (smaller) throws it won't be as bad.

For reference here is a picture from the manual. Notice how the Elevator servo rods are at different angles, top one being more in line with the servo.