I don’t think that a TRPT would work so differently from a rigid shaft as for SuperTurbine ™, except for a larger diameter which would attenuate the curvature in the middle, unless it would lead to stop the rotation. Perhaps also the unwanted curvature would be mitigated thanks to the lightness of the TRPT rotors.
To support the mass of the rotors, and thus compensate for their gravity, which (as for SuperTurbine ™) is augmented by lever effect with the length of the TRPT shaft in relation to the anchoring point, an increase in the tension of the TRPT is required, beyond the linear increase due to the length, leading to the requirement of a higher kite area beyond the linear increase.
A solution (for TRPT or SuperTurbine ™) would be the implementation of lifter kites all 10-15 m, although such a solution seems to be difficult if even possible.
Another solution would perhaps be increasing the elevation angle (leading to loss some efficiency).
A sketch below:
