OK - many googles later, I think I found the “right way” to manage the namespace in our xpath inspector.
Blast from the past from MattBoyd:
q: node values of xpath ("xmlns:a='http://schemas.microsoft.com/win/2004/08/events/event' xmlns:b='Event_NS'","/a:Event/a:UserData/b:EventXML/b:Param1/text()") of xml document of file "event.xml" of parent folder of client
A: ak166-cdss