I'm with ChuckW. A beginner shouldn't be trying a model so twitchy it needs negative exponential to tame the stick's midranges. That's also introducing radio alterations that take every bit as much understanding as the aerodynamic basics and a good start with the basics is, IMHO, preferred to jumping into "fancy" features before the simple ones are fully grasped. Most beginners lack the finesse of tiny stick movements anyhow and hit the stops in the control inputs.

Installing a servo so the control rod is perpendicular to the control movement axis at full extension (as opposed to perpendicular at neutral as most of us do for looks) also helps reduce that effect without programming.