The stance leg stays long until you are ready to release*. When you feel the pressure on the ski, stand on it. The idea is this: Balance in the top of the arc to get set up (balance, not angles), then relax the free leg and continuously increase the flexion and tipping. This is a really tough idea to describe--because it requires both active movement and intentional relaxation simultaneously. You'll have to figure it out, but when you do, there will be no doubt in your mind that you got it. The skis will just whip around and the pressure won't come until the angles are huge. Jay calls this "the Whoosh." If you are supporting yourself at all on your inside ski, you won't be able to get this so check your counterbalance if things aren't working.
From the long stance leg, i flex with CA and decrease CB, in transition i maintain CA and pull back my both ski's. I set the new edges, when it is done , i start to build CA the other side as CB,I relax the free leg and continuously increase the flexion and tipping.