Not so far. I flew the first Edge and the Edge 2 with no anti inverts. I've flipped the Edge 2 inside out once, after crashing, it wound up rolling all the way through the lines, had to get back to shore and sort it out. That's once in 2-3 years of flying Ozones with the anti inverts removed.
I have had the 07 and 08 ,9m,11m,and 13m I took the lines off all of them and never had a problem.....I have the 09 11m and 13m now, they are a 4 line so not an issue with the new kites. The 09 13m is the best off all the kites I have owned so far. Rhys from Kitepower has used this kite with 20m lines and loved it also.
Yeah had a nasty roll through once and, and the kite started looping, something tangled neat a wing tip, luckily I was far offshore. The kite kept looping and crashing and I managed to clip my leash onto the flagging ring and swam it in.
My advice is leave them on, they are a minor hassle, and the benefit of having them on outweighs any negatives.
Cya and
Goodwinds
Steve