Interested in doing a test as well to give a feedback with the other means I tried ; I give my address in PM.
Last week-end, I have done a preventive re-coating of my loved Pulsion after few 30 hours of use : a "hybrid" coating : nikwax on trailing edge (10 cm bandth width), same on the Leading Edge ; then to limit the weigh increase, I used the nanao-coating SealNGLide on the extrados; intrados with limited quantity of SealNGlide to allow for rapid drying of th inner of the kite if once wet ;
here the picture : on the right the LE and TE 10 cm width that were coated with Kikwax ; on the left, in the middle of the kite, SealNGlide.
It is now drying and "curing", but I have already measured that the weight increase is not measurable (less than 10 grams on 1600 grams ) ... Great !
It was a lot of work (hours, cost) but I think the result should be great : Nikwax is more "watertight " to water with pressure when kite sits on water waiting for the next gust to come and relaunch, while SealNglide elsewhere is deperlant to let the overall cloth dray an light...