You can fake attached events by converting the event node to a label for the action node. To do that, first reassign all edges connecting to the event to the action node. Then move the event over the action. Then use "Convert to Label" from the event's context menu. Now, place the event label at the desired position and adjust the reassigned edges' source and target ports so it looks like those edges connect to the label. Finally, use "Tools" -> "Constraints" -> "Port Constraints" to fix those edges' connection points for automatic layout.