You're entering the fun and exciting part of this amazing board potential. You're discovering what I mean by foiling da big Bertha when half of the hull is out and above of the water surface, bow wave just under the carry handle. Kind of a wide stance with front foot on the windward rail, back foot firmly pressing on the foam cover of the fin screw pit/cooler box. You're flying and reaching up to her topping up speed at about 12-13 knots.
Now, the tricky part is trying not to overturn the board : keep the hull always banked with the windward rail up and the leeward rail down. If you press too much the windward rail down, the board will suddenly overturn and throw you out. If the nose is flying to high in a gust, just sheet out a bit your sail, the nose will go down and off you go again full speed. In other words, you can adjust the nose pitch just by sheeting in and out the sail while maintaining the board always banked on her leeward rail.
You did that on a windy day with a 6.5 m2 sail which gave you the best time without rigging your monster sail. The beauty is that you can do the same kind of Serenity foiling with your 10 m2 sail but this time on a very light wind day, say 5-7 knots of wind ! Yes, you will start to appreciate that kind of foiling da big Bertha more and more, believe me, it's kind of addictive...!
Agree with your motto : everybody should have a Serenity in their quiver. The best light wind board ever designed. Nothing compares to her, even the fancy windSUP are no match to her.
Cheers and ride on !