Access Document properties in a Visio Add In

I'm writing a VSTO Add-in for Visio. Having a heck of a time getting access to the active document and it's properties. On ThisAddIn, I added the DocumentCreated event which has a document property in it. But I can only get the name property of the document from doc object. Any other property says it's not available on the document object. Saw some posts about the properties not being available in Visio like they are Excel/Word. If so, how do I access the document properties?

Private Sub Application_DocumentCreated(doc As Document) Handles Application.DocumentCreated
    myDoc = doc


End Sub