You quote some generalities about some drag coefficients, without replying about “will probably pull a lot more than a kite at Cl = 0”. Have you a reference of the pull during “backfly” compared to Cl = 0?
I don’t think the shapes in the table apply to the shape of the kite during “backfly”, which looks to be like
a flag without real consistency flying by the trailing edge (see the video between 8:30 and 8:42).
During my tests with a 4 line 4 m² ram kite, I was literally pushed back during normal upward flight while I felt no traction during backfly. But as I have already indicated, these are only impressions to be deepened.