You start sailing normal: the 2 kites on leeward site. As you gain speed the apparant will come more from the front. Then you steer the lower kite slowly to the back and then further to the other tack and steer the plane upward. With the glider you can control the hight and even steer to the left or right. Maybe in steering you have to add the control of the lower kite.

The lower kite is your "daggerboard" and adds to the lift. The higher kite is your "sail". If it works with car keys you probably do not need long lines and therefore can use small models. But you need steerable ram air kites (matrasses). How to control this rc ? I don't kow, but the people of SKYSAIL do. Controling the glider is obvious.

This is not expensive nor difficult to test and it probably works. Who has time ?

Johan