I guess the old adage applies: you won't know unless you try. check recomended throw from the manufacturer on the elevator. I also have a split elevator,so I take two sticks of balsa that are wider than the elevator.Put one on top and one on the bottom and band them together so they hold the surface flat. Then I center the servos.I bought a throw guage at the hobby store for 12 bucks but, you could hold a square up to the elevator to measure it. Generally, more is not always better. I realize that your elevator probably isn't flat cause it's an edge.