I seen this before. if my numbers are right at retail prices it will cost $300 to coat your kite and it will add about 8 kilos of weight. I think you want to try applying it at something like 1/20th recommended application level.
You are calculating coating both sides of the kite correct? Your numbers are pretty accurate for an 11M kite. Not sure how you came up with a 1/20th application level though. In order for the product to work I would imagine you should apply it as recommended. It's a spray on application from an aerosol can.
I would like to coat my kite lines with this.