"Might not loose it since a wood core2 - i maybe wrong but i thought the moses fuse was Al?
"..my feeling was footstraps already are not far enough forward." - One would hope that the footstrap locations on a standard production board + foil would be correct?
but a 50mm shift is pretty significant. Also, if anything, a shorter mast is going to require your weight to be moved forward. (You can think of this as the drag from the foil x strut length is partially countered by center of mass acting on distance behind the strut. Reduce the strut length and center of mass needs to move forward)
"Making strut plate to board longer moves bolt position relative to strut, perhaps putting more stress on the plate." Agreed but it is easy to make the plate as stiff and strong as you like..just make it a bit thicker and increase carbon skin thickness..very little compromise here? There should be no impact on the stresses applied to the board.
"What do you think of just angling the strut back?" I can see two potential drawbacks to this, though I suspect these are both more theoretical than realistic:
1) an increased chance of ventilation/cavitation being drawn down to the fuse and causing issues with the stab wing.
2) the increased bending moment in supporting the riders weight will tend to cause a torsional stress in the strut. possibly leading to an instability (humming strut?)..this may be hard to visualize - try holding something like a thin plastic ruler fixed at one end then apply a force to the edge at the other..it will give way by a twisting motion?
Your strut to plate connection is looking much better.
I would wrap extra carbon round the strut to increase the skin thickness at the ends & where the barrel nuts are. make sure the barrel nuts engage with the carbon skin, rather that just the core material. Then ad a final layer to cover the barrel nuts.