After discussion with Dave Santos I see that some of his ideas are interesting. An almost round pilot kite can have a L/D ratio of 2.4, which is not too bad for a very low aspect ratio. In crosswind use that leads to (2.4)² = 5.76, while a Nasa Parawing has a L/D ratio of about 2.8, leading to about 8, while a classic power kite has a L/D ratio of about 4 or 5, leading to about 16 or 25. Certainly the difference is important but some advantages of a low wing loading can occur, such like less wear, more regular efficiency, and the (mentioned by Dave) possibility of an iso-kite being able to fly in any directions without turn I mentioned in Reversible kite - #5 by Rodread topic for thin wings. These features could facilitate a full use of the swept area.
Now the question is how far it can scale. Then how building a network keeping the initial features of one unit.
I don’t think stacked kites are good for a crosswind use because the top kite covers a greater distance than the bottom kite.
I would rather see a network side by side, or if possible a network of side by side units making a single whole to facilitate both building and maneuver.