I think part of the confusion in this thread is whether you see ankle flex as an input or output. In the racing montage above the ankle flex is largely proportional to the pressure and relative position between the CoM and BoS. This flex is an output. It does not necesarily mean that the skier is acitvely using the calve muscle to do the flexing/exension. For instance at the release of the turn, which involves relaxation of the stance leg, the ankle is extending. This does not mean the skier is actively plantar flexing, more likely he is relaxing the joint a bit more.
The only frames with a lot of pressure are 6,7 and 8, and naturally there is more ankle flex because of the compression. This does not mean the skier is actively dorsi flexing. In all the other frames the flex is given by the boot, it is simply too stiff to bend without external turn forces.
There is some truth here. To my way of thinking anyway, plantar is really only "active" from skis flat to where you start to dorsi. Dorsi is created from "yielding" to the forces rather then an active pull....unless I get too far back too early, in which case I activley dorsi to pull myself forward prior to skis flat...this happens sometimes, but is more of a recorvery rather than an ideal. Plantar during the release then is also passive, just yeilding to the boot. However do not underestaimate how active plantar is during the "active" phase...if your calves are not sore after a day of skiing you are doing it wrong....or have really fit calves!.