I don't think the SDK needs anything special to allow this, Flex is
Flash after all.
I've built a few games on top of Flex, as Flex has the components I
required for the other screen outside the game itself.
I usually extend UIComponent, embed or load the SWF created with Flash
Professional, and make sure the main MovieClip in that SWF implements
and interface so the Flex app can communicate with the game itself.
Use the usual invalidation inside this component to set vars on the
inner SWF or resize it etc, and listen for events.
Then create a navigator, throw in all the different views required,
and the game view above, and your good to go.
Tink
