I would not move in more than ¾ of an inch in on the horn and 1.0 inch or 1.25 on the servo. Best is 1 " servo to 1" surface. If you have flown the UCD and think you need more throws than what the manual states I would check the CG. My UCD’s CG is 6 inches back from LE (move the CG back ¼ inch at a time until it handles the way you want). My plane will turn on itself at slow speed with all surfaces 45 degrees. I use 4/40 Central Hobby carbon push rods and Sullivan steel horns and Dubro servo arms. I also hard point the sufaces with a wood dowel and the horn / screws will not crush the soft wood.