Originally Posted by Mike Freas
I'm going to assume the prop size was selected to provide the best performance while keeping the Amp draw in check.
Not really. A slightly heavier lower Kv motor turning a bigger prop will have a higher propulsive efficiency than a similarly efficient higher Kv motor turning a smaller prop. As the electric motor weight is a small proportion of the total aircraft weight there will generally be a duration/range increase, at the expense of a cost and weight (and structural load) increase.