Correct import behaviour when WPAllImport is used.

countdown-import-helper.php

<?php
/*
Plugin Name: Countdown Import Helper
Description: Correct import behaviour when WPAllImport is used.
Version 0.1.0
*/


add_action( 'pmxi_saved_post', 'cdih_save_post', 10, 1 );

function cdih_save_post( $post_id ) {

	if ( ! function_exists( 'wc_get_product' ) ) {
		return;
	}

	$product = wc_get_product( $post_id );

	if ( $product ) {
    # works for simple products
		update_post_meta( $post_id, '_wpbpc_product_id', $post_id );
	}

}