How can I patch pmdevtopic?

OK, so, you don't patch the nodetype itself, you patch the htmlcode and other code-type nodes associated with the nodetype. Under Relevant pages are listed the htmlpage nodes which render various views of any node of the given nodetype. However, I don't think you'll need to alter (or add) any views of usergroupnote nodes. At this point, aren't we just talking about modifying handle_threaded_nodes (which is the htmlcode behind Recently Active Threads)?