See section 7.3.2 in the Tutorial and Developers Guide. There is an "ActionAfterCasMultiplier" option in the standard FixedFlow controller that you can override that specifies what happens to the parent CAS when all the children have been produced. The default is "dropIfNewCasProduced" but if you change it to "continue" the parent CAS will follow its children through the subsequent AEs.
~Burn
