Hi scott,
The general idea to separate a Dockable from a stack is just to drag&drop the Dockable away.
But… Dockables stick together due to the CGroupBehavior. The behavior can be modified by invoking CControl.setGroupBehavior. I suggest you try out CGroupBehavior.TOPMOST.
If CGroupBehavior.TOPMOST is too heavy, you might want to build your own CGroupBehavior. Depending on the target ExtendedMode you could then forward the calls to CGroupBehavior.TOPMOST or CGroupBehavior.STACKED (=the default behavior).
Let me know if these modifications help your.