I have a small modification for this very cool widget in order to be able to dynamically add new components to it.

Changed set content method and added a few new ones:

public function set content(value:Array):void {
_content = value;
}

/**
* Add additional accordions to the child list
*/
public function addAccordionChild(child:DisplayObject):DisplayObject {
var result:DisplayObject = super.addChild(child);
if (_content == null){
_content = new Array();
}
_content.push(result);
invalidateContent();
return result;
}

private function invalidateContent():void {
if (_content) {
removeAllChildren();
}

invalidateSize();
invalidateProperties()
contentChanged = true;
}

And also in commitProperties method after
contentChanged = false;

add:

accordion.removeAllChildren();
buttonDict.removeAll();
this.removeAllChildren();
addChild(accordionVBox);

And now you can add new childs to accordion by invoking:
collapsibleAccordion.addAccordionChild(child);

for my usage, i needed to change the
vertical and horizontal policy for the application to function properly.

works well out of the box.