unclear behavior for dynamic nav params and transient properties

[Stefan Hepper <sthepper@hursley.ibm.com>]

Hi,
for events you can declare at runtime new events that you publish by 
just returning them in pbia or he.
For nav params and transient properties it is not required that the 
updates you send in the UpdateResponse must be declared in the portlet 
description. However, it is stated that the updates must be executed.
As input it is stated that the portlet only receives the nav params or 
transient properties it has declared in its portlet definition.

Questions I have:

1. If we allow to dynamically create new events, why not new nav params 
or transient properties and provide these new nav params or transient 
properties with subsequent requests?

2. If we don't allow to dynamically add new nav params or transient 
properties, why don't we state that updates only apply to properties 
defined in the portlet description?

Stefan