Kite pulley

From experience it can be seen that near the ground the wind is turbulent and unstable, besides being of lower energies. But once the kite is up, sometimes it stays there for a long time. So if you could have a pully device, so that once the kite is up, you could send it heavier stuff up, possibly another kite, which would assist the first one!

You could always allow the "pulley" rope to be separate from the actual kite rope and flow directly down, or perhaps even further out, using a tiny air catching device at its lower end.

Then you could send out messages in a bottle to someone "down the line".

Instead of the pulley rope, there could simply be an extra string that can somehow be released when the kite is at its max, and then someone else further downwind would catch it, and pass it on and on.