Thanks! Very interesting story.
What about the fins, can you give some more details about them? Including the setup (twin, thruster or quad), foils and materials?
Thrusters with the side fins pointing to about 2" off the centre line at the nose work well, if they are toed to point at the nose as is std on a lot of surfboards they don't track well at speed, and on thrusters for fast waves I use a small rear fin to keep the board turning and tracking well.
Quads that are set up well are more versatile for all conditions and can handle more kite power and speed but the fin grouping needs to be closer together than a thruster fin pack or a quad will feel too stiff.
Side fins with an inside concave foil work really well for kite surfing i.e. fcs M3's .