For your application, have you considered separating your views within states, and only populate them on the "EnterState" event? You could employ modules that load up on that event, rather than preloading them with components.
The advantage of using states is that when your user comes back to opened states, they show themselves as they were left. Although the obvious caveat is the memory they take up (which you'd need to analyse in the Flex Profiler - assuming ur using Flex Builder 3 Pro). You can create the states dynamically, say when your user logs in, to load up the modules that type of user might need.
