Sorry I thought you meant the closed cells were open on the front. The whole LE is obviously open, maybe if it was closed it would be better but open I think water relaunch will still work. The kite just needs to catch the wind enough to engage the bridles. Maybe LE down with water in it could present a problem. Then you need to be able to rotate one tip up to drain the water sideways. Most foils don't seem to like doing this but nasa wings can. Maybe in the end closing the entire LE will be the best solution. I really can't see how it will add significant weight, must be between 3 and 5% extra cloth. Cloth would make up 70%-80% of the kite weight, so I would guess closing the LE is about 21 to 40 grams. Maybe he has tried. I thought just closing the LE on the peak would be a good solution for water relaunch with it. Maybe also with a closed LE battens wouldn't be necessary.
I am wondering in my head about other hybrid combinations, like only the rear third being single skin, or the center rear or the tips. I think it opens the possibility to create flapping when depowered, making a positive effect where the kite will sit further back in the window and drift better,and be more stable like with tails on kites. The peak already does this, inflatables like the cloud as well, the pyscho4 as well but in a different way. With the single skin on the rear it would also bring the CG forward. It could make for a very good surfing kite. Hmm I'll throw it on the back burner but if no one trys this I will butcher a kite my self
Your speed single skin has inspired me! Do you have a link to it?