The example you gave is a weight-shift trike, not 3-axis control. The pilot shifts his weight by pushing or pulling on the bar (in his hands). Note the joint just below the wing. That is a pivot point. There is no solid connection between the wing and the pod. I hope you mean just the seat as an example, and not the whole design. Not that there is anything wrong with weight-shift trikes. But some pilots have a hard time transitioning to/from them and 3-axis control since the control action is backward. I, myself, have sometimes wondered about such a structure with a rigid mounted wing and conventional 3-axis controls (like Nickel's Falter 1).