In the assembly manual for my GP Super Chipmunk ARF, it states that the plane should be set up with different elevator throws. Not just the normal High/Low rates but left and right as well.
On low rates it states Left 1" and Right 5/8" . High Rates 1.25" (left) and 1" ( right).

Can anyone explain why this is so and is it mandatory?
Also what is the impact if one chooses not to set up the model this way?

The rest of the model is pretty standard and it has a DLE 20 in it.

Thanks,