This topic initially was about torque transfer systems. So the aim is not a detailed analysis, but rather an overview of the major features. In my first message I wrote: “Probably torque transfer systems don’t allow to reach so high height as tensile transfer systems…” (“tensile transfer systems” are pulling (yoyo) kites), without taking account of the rope-drive system you mentioned, and which allows to reach a high altitude compared to the rig size. As this system scales, the rigid parts such as the propeller and the pulley undergo an almost cubed weight increasing that makes a limit.
To my knowledge the only torque transfer system that can do without rigid parts aloft is the Rotating Reel System . In the other hand the diameter of the ground rotor must be roughly the same as the diameter of the flying rotor, and its aim is rather from medium to high scales.
As there are topics about realizations using different torque transfer systems and relating pros and cons, I think it is not needed to open new topics.