This video and the reeling parachute system is described on Zhonglu High Altitude Wind Power Technology - 中路高空风力发电技术 and Slow Chat - #71 by Windy_Skies.
An example of depower (for reel-in phase in yo-yo mode) is shown just after the start of the video, then along it. I wonder what force the inverted and flapping parachute exerts: maybe its drag is like the drag of a flag, so not quite neglecting.