From both a maintenance, operational cost and engineering complexity point of view I don't see this as viable, but I'm more than happy to be proven wrong by a party that brings it successfully to market. Meanwhile, any place where this kite system would work is one where a regular HAT would work as well and long term (25 year lifespan) total cost of ownership and $/KWh generated will be pretty easy to determine by deploying two systems side-by-side.