With a standard servo the rudder on mine has quite a long throw. I can't imagine that having more would be effective, but rather just stall the rudder and make things worse. The model does.need good rudder authority to fly well. I had a problem with my set up where the ground handling rudder control to keep the plane tracking straight was the opposite of what was needed when the tail lifted off. This obviously led to some interesting take offs. Once everything was aligned properly things got much better.
David