"I'm curious what Mark of MM recommends on this, i.e. setting the Wing Rigger directly over a wheel."

Charles- There is no problem with positioning the chassis and wing cradle all the way to one side or the other to counter a crosswind. The PW-5 has a lightweight wing, and when rotated to the vertical position, it becomes a pretty big sail. Moving the vertical column to the UPWIND side and locking the axle (!) can help by giving more lateral support. Remember that you are not actually "setting the WingRigger directly over a wheel." The axle support tube is ten inches long, so the vertical column is offset. (Not so much on the side the saddle is rotated to.) The most important step is securing the lateral movement with the axle lock knob (and checking it before moving!)

However, if you want a longer axle, contact me and we can discuss options.