I genreally stop sailing between 22 and 25 knots average depending weather wetaher it is a gusty Southerly or Westerly or a constant sea breeze.
Whilst on the water, we do not shy away from the kite as I feel it steadies the boat more and makes it easier to gybe in big breeze.
Max wind I have raced with the kite is 36 knots average, gusting 42 (Recorded at the airport) on the Tornado. We held the kite for all 3 laps and went for a big swim whilst coming out of a gybe on the last lap. I became trapped under the boat and seriously thought I was going to drown. I am a little smarter from that experience and will abandon racing again if it ever reached those limits again.