You could put the @RequestParameter in an Event scoped Bean (eg. myFormHandlerBean) that just handles the form submit. Outject the Bean that actually handles the entity (eg. myEntityBean) and then use pages.xml navigation to redirect to a page that display the Bean that handles the entity.
I am a newbie... and I am only guessing but.. have you tried with:
@In(value="elementId;" scope = ScopeType.SESSION, required = false) protected Long sessionElementId @Out(scope = ScopeType.SESSION, required = false) @RequestParameter protected Long elementId;
IMO that might outject elementId and the inject it into sessionElementId. (IMO you need to set the value of the annotation because the name of the injected variable does not match the name of the outjected one).. but I am not sure if my understanding of @Out and @In is correct... maybe I am completely wrong...