Hi @rschmehl, numerous publications validated until some degree the “two main AWE modes” (fly-gen and yo-yo). As you know a third mode will be highly represented in the next awec2021 : tensile rotary power transmission (TRPT), with @Rodread , @someAWE_cb , @Ollie , @tallakt :
Rotary Kite Turbine Development
Roderick Read, Windswept and
Interesting Ltd ;
Rotation compensator based cyclic
pitch control for Rotary Airborne Wind
Energy Systems
Christof Beaupoil, someAWE Labs S.L. ;
Design Analysis of a Rotary Airborne
Wind Energy System
Oliver Tulloch, University of Strathclyde ;
The Pyramid, a TRPT rethink
Roderick Read, Windswept and
Interesting Ltd .
The last one leads to a new design (The Pyramid) as well as a computerized scientific method to better understand and maximize the potential of TRPT. You will find again some of the elements of the analysis of the now defunct Rotating Reel Parotor for which I thank you and others for shedding a tear 
.
I would suggest that each of these four presentations be labelled “TRPT” to allow listeners to make the link, ending with the perspective of the Pyramid.