Stumbleweed said..
Faff, I ride Armstrong hs2 780 with the dart 140 tail, +0.5 shim, cedrus wing mast (90 or 72), foil positioned at center of mass balance point of board. Board is a 78 L Emissary. I ride f-one wings of different generations (mostly newer). I mainly ride in the Columbia Gorge so generally there's swell but certainly not always big swell. Generally I looks for mid-strength days to work on speed (17-22 kt). I'm 85-ish kg
I heard that original Armstrong HA foils were very technical. But if that's not the foil I think it is, then you should have no issues at all hitting 20 knots with that setup. Ride higher on the mast. Bear away as much as possible in a gust in a flat spot, moving your weight forward as the front foot pressure rises. You don't need to be hooked in. Might consider taking off the board leash, so that the board does not fly after you in a crash. (Would need to know how to body drag, of course).