Steve,

There is no need to complicate things:

Any headsail (jib, spi, hooter) lifts the bow, much like a windsurfer's sail inclined to windward. The differences in sail shape are less important then the relative positions of the sail's extremities.

The tack, hoist and clew of a sail define a plane. In the mainsail, this plane is vertical (or as inclined as the mast is raked aft).

In any headsail, this plane is inclined to windward, so the sail thrust always has a vertical component lifting the boat.

Placing the headsail further forward increases the leverage of the vertical component and raises the bow higher with the same sail thrust.

Simple, isn't it?