I've been playing around with a cheaper 2.5m nasa star, EU based, less than half price, have to make your own handles.
www.born-kite.de/?language=en&cPath=21_23&cat=c23_Nasa-Star--5--Nasa-Star--4--Basic.htmlMy use case is a single broad reach out to sea on cross onshore days to make a good angle back downwind. I don't think this is useful for safety or upwind, here are some thoughts
Needs lots of wind, 15kn not enough, though it pulls hard
Launching a kite in very confused conditions while sitting is tricky. Easy when it goes right, but not always that easy.
Bridles have a habit of wrapping around the nose of long boards, need to shorten them. Shorter board easier
If the bridle gets tangled, hassle to unwrap in the water, kitemare
Kite is quite slow, tend to overtake it.
Standing on the board with only the kite pulling is tricky, harder than with a wing or SUP in messy conditions, this will be an issue for most people.
I'm tempted by a pocket wing as people seem to be having better luck
Another video of some success
www.instagram.com/p/C9KIAvpo7PA/?hl=en-gb