If you fly the kite anywhere near its sweet-spot rating, it SHOULD fly just fine for what its designed to do without changing a thing.
"What it's designed to do" is a is a very broad statement. Many people like to make their kites do things that the designer may not have had in mind.
Modifying a kite - be it through ballast, bridle changes, frame changes, whatever - is fine and should be encouraged, providing the person doing the modifying keeps the golden rule in mind.