Dan Allen, Author of Seam in Action book and red hat Seam core developer, states
Since conversations are stored in the session, two requirements must be met:
- Conversation-scoped components must implement java.io.Serializable.
 
- The session timeout, defined in web.xml, must exceed all conversation timeouts.
 
As far as i know is that The JSF Tree can be stored in The client side, enabled through web.xml context param
<context-param>
    <param-name>javax.faces.STATE_SAVING_METHOD</param-name>
    <param-value>client</param-value>
</context-param>
But keep in mind bandwidth issues when using this kind of configuration