There is Zhonglu High Altitude Wind Power Technology - 中路高空风力发电技术, a train of parachute kites, which reached 512 m altitude.
An aligned (not crosswind) AWES like this, or a stationary AWES, would allow to mitigate tether drag which is seen as a limit for the reachable altitude of crosswind kites as specified on the video (from 0:43) of https://windtime.it/, but more details and calculations would tell the story better.