Yep, got the GPS onboard but batteries went dead after 2 min...next time for sure I'll get new ones.
As said, this was a short 2x1 hrs test, so still a lot more tweaking and fine-tuning to do with sails and fins like I'm doing with HS105. I felt I can further extend the range of use just by switching fins and I bet a 32 cm fin would still be rideable for extra speed once overpowered in 8 knots with the 10.6 sail: large fin for low speed in low wind, small fin for high speed in higher wind.
Agree, the large 70 cm fin makes the board more slow to react during transitions than the Shallow 41 cm fin, but I've found that when standing on the tail just behind the fin and rolling/tilting the board on the appropriate rail, tacking (tilting the leeward rail) or jibing (tilting the windward rail) can be done very quickly with a very short turning radius.
With the 10.6 sail, the mast track was set at 50% . I did notice that when feet placement were located between the carry handle and mastfoot (i.e., body weight more forward), the hull glides and slices more gently through small chop when going deep upwind. When I stood behind the carry handle (i.e., body weight more backward), the front hull kind of splash every top of chop, with greater vibrations being transmitted along the entire hull (you can actually see the nose tip shaking up and down). So, more stance tuning will be needed, I agree !