Please can you support this statement by providing some reference? Thanks.
No, as it is a vertical path, the only relative airspeed coming from the vertical descent of the kite, not from the wind speed, even less the wind speed added to a relative wind which does not occur against the wind direction. Indeed reel-in speed of 16 m/s can occur while the kite flies upward then “backflies” vertically without approaching or moving away from the station.
An example of vertical path is given on the figure 1.18 on:
https://hal.archives-ouvertes.fr/hal-01759173/document
The trajectory is almost vertical. The reel-out and reel-in distance is deduced from the elevation angle of the AWES between the bottom and the top of the trajectory. As a Magnus-Effect-Based AWES would produce energy by using this vertical trajectory, one can deduce the same for a “classical” kite.