Stoked you've got it - let us know how it goes

I moved the Tuttle box forward 15cm (early days with the Naish WS1 which has less lift) - not sure if it's necessary with the SS wing.
You can always try C position if you need more lift.
I glassed the sides of the Tuttle box to the top and bottom of the board - a glass I Beam.
I would get a few sessions in before you reinforce the box - then you can reinforce and move it forward at the same time if you want your back foot over the mast.
Rear footstraps were maybe a touch too close to the centreline for power upwinding but good for downwind.
Front position's great.
The big spread (44cms) between the footstraps works for me - transfer weight on the back foot to get going in light winds and transfer weight well forward to counteract increased lift when flying down waves and swells