I'd recommend building in all the adjustable stuff you can...leadouts, rudder, control ratios, etc. That way, you can adjust one thing at a time and
learn a lot more from that one model. The latest discovery for me was that since the lines would go slightly slack during a few of overhead maneuvers, that a wee bit of right thrust in the engine would make them tighten up quicker. I knew this from my teens...on combat models, but had not tried it on a stunter. A
little bit is a good thing. The leadouts will then be slightly forward, to return the plane to tangency.
Basic rule is that you want the model flying tangent to the circle, so it is not draggier than needed. That leaves more thrust for accelerating the model back to cruising speed, and speed = line tension. Lack of line tension causes, uh, you know...crashes. Maybe even most of them. Get your model trimmed before you push it too hard! You should not have to compensate (handle wiggling, whipping, etc.) for your model. Trim the model! That includes: line size, type, and length, handle adjustments, propeller brand, and size, fuel tank height, muffler pressure or no, nitro content, etc. It all matters. The better it flies, the better you fly, and the longer it will last!
Steve