>I have just had a same named thread replied to by Sergey. His response regarding the same did what UT allows me to do, but there was a different result I was expecting. Of course this involves changing the interface here, but if you do find it practical please consider the changes.
From what I understand, you seem to want the dynamic treeview to kick in no matter the number of messages. So far, you have your account configured for the default value of 400 messages. When that limit reached or higher, the treeview will become dynamic. Have you tried using the minimum value of 50?