Me - 85kg, Armstrong 88l, Armstrong 1550V2. A few gybes in.
In early days to get flying and stable feet-position was critical, but after a bit of experience I can be much more lax/lazy on where I put feet (though does matter in learning to gybe).
So, I expected moving mast 1cm either way would be easy to control lift and stable flight but find big difference in control of flight. I can half-understand that there is a position where the mast is optimum relative to board rocker and volume for take-off, but can't see why it affects flying so much (to me anyway)
Isn't moving feet same as moving mast?
I would speculate that the difference is that you are changing the lever force. If you move the mast back 1cm, your front foot has a much larger lever effect - you now need to move it much further forward to accommodate for the small movement of the mast relative to where your back foot is. If you move both feet back the same amount and apply the same pressure then it should be the same performance, but when you put weight on the front foot it is likely it is ending up in roughly the same spot all the time, and the difference in pressure required is probably quite noticeable.
Not quite related to your question but my personal experience is the higher aspect Armstrong foils are quite sensitive and I struggled a bit with longer boards - I definitely found things a lot easier with a smaller board and the foil forward a lot more than you would think. Probably less of an issue with the Armie board combo but still seems to require the 'forward geometry' as they put it.
