My experience is that single line kites do generally scale and over a very wide range- provided their weight/area ratio stays relatively constant.
The smallest ram air flag kite is 0.75 m span, 0.35sq.m, 0.1kg. The largest is 45m span, 1250 sq.m, 360kg. The mini’s weight/area is around 0.28kg/sq.m, the mega’s is 0.29kg/sq.m. They both fly well, and very similarly, with good recovery and no weaving. The mega is more than 3,500 x’s the mini by area.
Single skin kites can also be scaled up until fabric and corded reinforcements reach their strength limit without any significant increases in weight/area- but in very large sizes would have far too much pull to be practical for kite event flying.
Another insight into how a single line flexible kite scales up. The weight/area is almost the same for small and giant kites, so that the exponent K = 2 by square law: the weight increases linearly with the area.
A further study on single skin power kites would be desirable.