Just discovered that if you add an item to the Everything context menu with the "Show this item when the Shift key is down" option, it is also accessible through Menu:SHIFT-File (= Click on File with the SHIFT key pressed down or press Alt-Shift-F) !!
Simple, elegant, not obtrusive ... very well done!
(The F / File will depend on the Everything language. For example: in German this would be D / Datei (I think ..))