So when switching the xml or scene before that loading is done, that event can't be fired of course, but onxmlcomplete or onnewscene events would fire of course. When they are missing then there would be either an usage-error or a bug (but currently there is no known one here).
Thanks for taking the time to reply. I'm sure I'm using it correctly, but I'll try to set up an example and get back to you.