Speculation can be fun. Having a stiff wing that can twist at the tips to spill off gusts would be cool. That's basically what happened to sails, they twist off gusts at the tips.
Kites are alot more complex than sails though. Much more 3 dimensional forces on them. Also, they have to relaunch, sails didn't (oops not past tense to everyone, just me)

I know I am glad I don't design kites because I bet they have to juggle performance with user friendliness and consistently (probably) have to give in to user friendliness (water relaunch while sitting there and pulling one line, ability to talk on beach ad-naseum w/o looking at kite, etc. ) over kick butt performance. Getting both in one kite must be an impossible challenge.