Timbo.

There is the front #1,2 and the back or #3 as we call it.

The twist in #1 can be controled between the foot/bottom/boom, whatever you want to call it and the hounds 25' from the bottom. There is essentially a torsion rod inside the wing, the more we ease it out, the more the front twists. above the hounds, 25' plus, the wing does not twist in #1,2

As for #3, we can also control the twist between the base and the hounds and above. The control arm is integral to #3 at the 25 foot mark so it effects twist above and below that point.

Roll? Well we call it heel angle and yes we do use #3 twist to control the heeling force, or moment, on the boat. We don't adjust it by gust, we simply set it up right for the conditions on that leg of the course and forget about it. If there's a gust we simply ease the mainsheet (Angle of attack if you are stuck in aircraft mode of thinking).

The twist in #3 is opened up in big breeze as it reduces the load generated by the top part for the wing and in turn moves the heeling moment lower, closer to the axis of rotation for the boat, which allows us to carry more power for less heelinig moment, and in turn go faster.

Generally we set up twist for a leg and forget about it. After that everything is crew position and mainsheet, and of course good steering.