I agree with Andreas when racing in under 20-23 knots. I am an amateur, but have raced formula against several of the top racers in the world on a number of occasions. In 10 - 20 knots with identical equipment, they always manage to point a couple of degrees higher with more speed. Downwind, they run deeper with more speed. It takes time and practice to do what they do.
Learning to manage a formula board in 25-30+ knots is where the real challenge comes in. It takes boldness, and big ba##$ to push yourself to practice in windy, rough conditions. Running downwind in 30 knots of wind in 1 - 1.5 meter chop/waves can result in big time "slams" over the nose until you get comfortable. Be prepared to put some dings and dents in the front of your board until you get a lot of hours under your belt.
I am somewhat comfortable up 23-25 knots, but over 25, I now stay on the beach. I am an "old guy", but the younger sailors can push the limits and be a little more relaxed while doing it.