Technology

Contentious. Thethering increases power production by restricting the "sail movement power". The blimp part is highly/perfectly aerodynamic, and the betz limit means that a turbine does not fully "act like a parachute". Ground vehicles that proved faster than wind speed directly upwind could use similar principle to turn a propulsion prop, that increases forward/apparent wind speed generating more power.

This relates to same incredulity for faster than wind upwind ground experiment, and needs experimental proof. But principles of sailing are indeed magical, and simply generating enough power to move forward is extremely useful, even if tacking were needed.