Since the rules specify maximum span and chord for wing and tail, and you want to maximize lifting area while staying at minimum weight, there is not a lot of flexibility in the overall layout of the plane. The motorstick length, especially this year with small props, is more or less set by the rubber length. The tail moment is variable to a point, but impacts stability, duration, and weight.
That said, there have been, and continue to be, a variety of designs. As noted by retired1, the wing curvature, perhaps ideally an elliptical shape, can be simple to complex. There have been flat wings with tip plates, simple, and complex dihedrals. Same with stab, with tip plates or a central fin. Tip plates tilted or vertical.
But, within the given rules, you won't find a radically different planform.
Still, plenty of variables to experiment with. Some may include airfoil (thickness), the planform deviations already noted, rubber length (width), prop pitch, prop planform, prop construction (flaring, etc.), winding methods, torque at launch, tail moment, CG, wash-in/out of various panels, tail tilt, tail or rudder offset, wing post height, and many others. While from a distance the planes look similar within the given rules, the numerous variables can make or break a "similar" plane.
With all these variables, a deep and complete log book is one of the most critical elements of successful SO Wright Stuff.