When you're looking at a plan for an aerobatic model that has a proven track record you're wise to accept the design as it comes.  As Dick has pointed out the details inherent in the design were not put into the plan on a whim.  Rather they are products of evolution from a series of models that led to what you see in front of you.  If the wing is set up with an airfoil transition that seems to favour tip stalling it was almost 99.999% sure to have been done because it was found to be needed to fly the model the way it is made to fly for the events it has to fly in.

It's like the stabilizer anhedral in one of the mid 70's pattern ships.  Everyone thought it looked uberkewl but when you read the details in the article about the design evolution it was done because the original stabilizer was too high and it didn't knife edge or something the way the designer intended.  So it was cut up the fuselage to move the stabilizer or somehow lower the stabilizer.  Since that model had a fiberglass fuselage cutting the fuselage would have been messy at best.  So he did the easy thing and put anhedral in the stabilizer.  It worked, he won a few big contests and others followed and put anhedral in their stabilizers wether it was needed or not because it was thought that the anhedral had magical powers.....

Now if this was for a scale model plan where only one was ever built and the designer basically said it was an evil demon to fly then you'd be right to be asking about fixes.  But on models that come with a proven flight performance you shouldn't bother trying to second guess until you fly the model.  If it doesn't suit you then it becomes more a case of you needing to adapt to the model and learn to fly it within the bounds it presents so that it can do the things it is intended to do.