Y configuration is often seen as an ultimate. Several wings sweep their common annulus, while the main tether is fixed. Launching could be achieved by using a ground area equivalent to said annulus, the station being at the center of said ground area, and by using the generator(s) as motor(s), VTOL being achieved by considering the set as a rotor.
Y configuration could allow to maximize the space used by approaching the Betz limit, and mitigate tether problems (drag and weight). However Y configuration could be too dependent on a computerized control, and the presence of a single main tether would constitute a serious risk. We dare not imagine the consequences as the tether brokes. It is a reason of the possible suitability of a design like Dr. Beaujean's airborne wind turbine comprising several fixed tethers, and where the blades are the alone moving elements.
A theoretical advantage of AWES over HAWT is a not limited space. And AWE aims high altitude wind energy. So, IMHO, AWES will only be able to compete with units that are much larger than the HAWT which will have moreover made great progress. The current prototypes can be seen as first means to explore AWE potential, not as achieved systems, and that for and until a while. It is also why we don’t see significant intermediate markets.