Promoted Properties vs UDP

Broker properties are divided into four categories:
Properties that relate to a specific node
Properties that relate to nodes in general
Properties that relate to a message flow
Properties that relate to the execution group
Experiment1
* Promote Property for main flow - Input Mq node Queue property and Output node Queue property
The properties are seen when seeing properties of message flow
Properties are promoted to message flow level
After creating bar file ,just the overriding properties are changing with new values
After overriding with new values,the bar file is just saved WITHOUT RECOMPILATION.
If we recompile,again it get backs to the same old value;the overridden values are not getting effected.
Just deploy now;The overriding properties works fine :)
Experiment 2
* Subflow is used in the middle of MQInput and MQOutput node in the main flow
*The subflow has a MQOutput node whose Queuename is promoted
*As it is promoted,the queue name has become the subflow's configurable property
*Now,when subflow is referred in the main flow,the subflow's property is shown.But it says,the subflow's promoted property cannot be overridden ."Property override is not supported on the subflow node"