The PureMVC Framework Code at the Speed of Thought

Hi,

Imagine an pure AS3 (not Flex!) application like this:

- A main-application, which provides several UI-Elements, forms, menus etc.
AND
- a game-application which can be started from our main-app.

- We have no flex-modules, just 2 different MVC-Trees to seperate Game-code from MainApp-code.

Both apps have a MVC-like structure. So we decided to use the PMVC-Multicore-Version.

Some questions popped up:
- is it valid to interact from one core to the other like this??:
  (e.g.: GameCore wants to inform MainCore):
    -> ApplicationFacade.getInstance("main").sendNotification(SURPRISE);

AND

- maybe this is a stupid question, but:

Why can't we just setup 2 SingleCore-Facades instead of the multicore approach? Thus they are different singletons there should be no interference? Would that work? What's the advantage of multicore?

Please enlighten me!