Hacky. Past this into a WP-CLI shell, for example, to grab an export of postmeta to paste into Debug Bar Console on another server.

debug-bar-console-import-postmeta.php

<?php
$source_post_id = 123;
$dest_post_id = 456;

foreach( get_post_custom( $source_post_id ) as $key => $values ) { $value = array_shift( $values ); printf( 'update_post_meta( %d, %s, %s );' . PHP_EOL, var_export( $dest_post_id, true ), var_export( $key, true ), var_export( $value, true ) ); }