Modify WooCommerce to consider backorder status as instock

Question

When using the below snippet, WooCommerce would order products based on stock status value:

1. instock
2. onbackorder
3. outofstock

add_filter( 'woocommerce_get_catalog_ordering_args', 'shop_sort_by_stock_amount', 9999 );
 
function shop_sort_by_stock_amount( $args ) {
   $args['orderby'] = 'meta_value';
   $args['meta_key'] = '_stock_status';
   return $args;
}

However, I want WooCommerce to consider onbackorder as instock so the position orderby remains the same.