Drupal behaviors attach to form load
Got it after a number of days searching: 

(function ($) {
    Drupal.behaviors.hotTopicsResearch = {
        attach: function(context, settings) {

            $(document).bind('drupalOverlayBeforeLoad', function(event) {
                $('#simple-dialog-container', context).dialog('close');
            });
        },
        weight: 11
    }

})(jQuery);


The other events seem to have the wrong order. 'drupalOverlayOpen' almost works except that the editing overlay never 'becomes active'. This is why I was trying to work on the target editing screen events rather than the open dialog. 

overlay_paths without there being'use case documentation' it looks like it only applies to menu items. How to manually use Drupal 7&#39;s admin Overlay? shows you how to add content nodes to the admin paths. This displayed my node in the admin overlay, but without the background context being visible - defeating the point - and with some further quirks.