Sitemap functionalityBrowser Info Environment
I did briefly consider other functionality. However, my thinking soon became tangled in security violations and edge cases. For example: consistently resolving what would happen if you do anything with the page the sitemap popup is currently above; once given greater powers, access to those powers needs to be managed (which comes back to your question).
Hence I soon decided that limiting it to navigation was the most realistic approach to providing something useful.
If you wanted to change this behaviour, the place to start is line 31 of the quick_links model. Rather than the callback being to select the node, it could probably be changed to callback a menu popup. However, doing such a change without resolving the sort of thing I note above may lead you into a lot of trouble.
As always, thanks for the quick reply.