Possible route to passing duplicate menu items in Menu Breadcrumbs through a filter for use in the theme. Per https://github.com/jchristopher/menu-breadcrumb/issues/7

menu-breadcrumbs.php

<?php
/**
 * Retrieve the current Menu item object for the current Menu.
 *
 * @since       1.0.0
 * @return      bool|WP_Post    The current Menu item
 */
public function get_current_menu_item_object() {
	
	$current_menu_item = false;
	
	if ( empty( $this->menu_items ) ) {
		return $current_menu_item;
	}
	
	// Setup an array to store all possible current menu items
	$possible_menu_items = array();
	
	// loop through the entire nav menu and determine whether any have a class="current" or are the current URL (e.g. a Custom Link was used)
	foreach ( $this->menu_items as $menu_item ) {
		
		// if WordPress was able to detect the current page
		if ( is_array( $menu_item->classes ) && in_array( 'current', $menu_item->classes ) ) {
			$current_menu_item = $menu_item;
		}
		
		// if the current URL matches a Custom Link
		if ( ! $current_menu_item && isset( $menu_item->url ) && $this->is_at_url( $menu_item->url ) ) {
			$current_menu_item = $menu_item;
		}
		
		// Add the current menu item to the array of possible menu items, reset and repeat
		if( $current_menu_item ) {
			$possible_menu_items[] = $current_menu_item;
			$current_menu_item = false;
		}
	}
	
	// Pull the first menu item by default, but filter it so others can be chosen.
	if( isset( $possible_menu_items[0] ) )
		$current_menu_item = apply_filters( 'menu_breadcrumb_current_menu_item', $possible_menu_items[0], $possible_menu_items );
	
	return $current_menu_item;
}