It seems to make sense to me to attach the tether from the ground station at the center of gravity at the fuselage, and the triangular bridle at an extra fuselage at the end of the inner wingtip, and then angle the outer wing down some, adding some anhedral to the plane.
My assumption is that this forces the inner wing to have a zero degree, or close to it, roll angle (be in the same plane, or close to it, as the triangular bridle), and also that you need the anhedral to give the control surfaces of the outer wing a way to act perpendicular to the axis of rotation, with this zero degree roll angle. And you’d use anhedral instead of dihedral to, like @Rodread often says, help expand the rotor.
If you also make this extra fuselage longer, you could perhaps counteract the pitching moment of the wing at the inner wing tip. If you wanted to counteract the pitching moment of the entire wing you would attach the triangular bridle at a longer fuselage at the center of gravity though I think, which would then hopefully reduce the need for an elevator
What do you think, dear reader?
I think the anhedral question is related to Cyclic pitch control for Rotary Airborne Wind Energy Syst. using a rotation compensating slew plate where I think adding more anhedral or dihedral, angling the blades up or down more, would make the rotor more controllable but also less stable. What do you think @someAWE_cb?
If you don’t do this and attach the triangular bridle at the fuselage, I assume using a dihedral wing is more stable and with that makes more sense.