I can add something about using a formula board--with far outboard footstraps--for free-ride foiling with sails smaller than 7.0; namely, it is NOT comfortable. If you keep your back foot free and placed at or near the middle of the board (to control side to side roll), you have to stand crabbed forward. It works, but it is not comfortable. You need to get the front foot inboard.
I have experimented with stick-on footstraps placed inboard for free-ride foiling. This has worked very well for a better stance and balance. Problem is that the stick-on pads come off too easily. I keep an inventory of sand paper, acetone, industrial contact cement, and automotive two-sided foam tape in the van to re-stick.
With the NorPac foil board now, for free-ride foiling, all of this is completely moot. The formula board is now reserved for a race foil and big sails, for which you DO want to stand far outboard.
The default is a deep tuttle box, but since they make them custom, you could always ask them to make a slider. They sell them through Sailworks.
For deep tuttle they include really strong reinforcement to carry the cantilevering force exerted by the foil. They use extra stringers attached to the side of the finbox and embedded forward inside the board foam. This effectively makes the finbox some 15" long.
Before they got busy with making foil boards, I had them modify a formula board by moving its finbox 3" forward. They did that and included the stringer reinforcement. Nothing will tear that finbox out now.
No, no cutouts. Since the wing begins to lift the board even at sub-flight low displacement speeds, you don't benefit from cutouts. My formula board has cutouts, but I can't tell the difference between it and the NorPac when getting going from start to flight speed.
I have 2 boards. for foil starboard f type 158 l, weight 10 kg and for strong wind starboard iconic 127 l, weight 7 kg. I two days ago under wind 8-10 knots tried isonic with foil. The weight difference of 3 kg for did not affect the takeoff. But the width of the stern affects the stability and control of the Foil.