You almost never need to add cork to the ankle bladders unless you have really skinny ankles in a shell that provides a "comfort" fit. If you need more heel hold down power then usually you will add more cork to the tongue.
I attempted this. However it seems to make my overlap at the instep crisscross and prevent me from fully tightening buckle #3. Ankles still have some looseness to them. This is all in right boot. Left is perfect.
Sometime before next season I need to sit and play with some additional Omfit in the ankle pockets. Plenty of time for that these days.