Umm... just change one or the other by one hole... fly it and see the result. Its possible to get too much throw.

If you still feel the need for more... try again.

If the change of which hole has no appreciable effect on how the plane handles at large stick movemnt... you have gone beyond useful control surface travel for the airplane. Time to reduce throw and increase control sruface area (or move up to a dfferent airplane)