Yesterday I was practizing in Muiderzand in 18- 25 knots of breeze. In the morning I just managed to do some trapezing downwind.
Standing on the back the boat accelerates very quicky to speeds over 20 knots with the nose 20 cms out of the water, the next moment it slightly dives and the footstraps saves you, if you make the mistake to luff the boat shoots into the air.
Under 18 knost you have lots of control and just walk over the side to keep the right longtudinal balance with the leeward nose just out of water. Over 18 knots life is a balancing act. When I was in the toestrap on the transom the boat felt very light and quicky accelerated away, but it feels that the boat can come agressively out of the water too. Taking a step forward and leaving the footstrap does not feel like the right option though (maybe an extra toestrap?).
If the boat lifts you bear away and you try to control the boat with the sheet, a long sheet is certainly helpful here. In these conditions the margin for errors is small. One moment the boat slighty dives and you hang with yout toes in the footstrap and the next moment you speed away. If you do not control your rudder perfectly the boat will move like a wild horse.
Practizing will be the key to master it and to feed your confidence that you control the beast and not the boat you. If you do right you will sail away form the others but if not the guys who will just sit on the side will pass you.
Maybe it would make sense to sail with somewhat less boardrake as we do not need that much lift in those circumstances.
Later the wind picked up and I even had problems to keep the nose in upwind! Once the speeds is over 14 knots the boat wants to come out of the water too especially on the short waves of the Ysselmeer.
Over 22 knots trapezing downwind didn't feel like an option and I sailed the boat flatter with a very loose sheet still reaching amazing speeds. If you powerup the boat too soon it starts digging in and you are slow, once you can free the boat it speeds up and can be controlled with the sheet and rudder, even in the big gustst. There seems to be threshold which you have to pass. At a certain moment you cannot control the boat completely by fully hiking out; the nose will start to dig in . If you switch to a more light footed mode you pass the threshold and you can sail very fast and very deep. The fast guys are the guys who stay out of the slow zone and have the best skills to switch modes to pass the threshold and they will even hike out again.
In pratice I use a GPS to see my speeds. It can help you too because you will get a better understanding of the boat and it will improve both yout trim and steering.