Quick way to hide protected meta data via a plugin. More robust than the _ prefix.

meta-data.php

<?php

add_filter( 'is_protected_meta', 'hide_meta_data', 10, 2 );

  /**
   * Set our metadata to be protected, will not be seen in administration,
   * unless the plugin is deactivated.
   * @param  array       $protected protected values
   * @param  string      $meta_key  current meta key
   * @return string/bool            $protected or true to add
   */
function hide_meta_data( $protected, $meta_key ) {
    if( 'shipping-preference' == $meta_key ) return true;
    return $protected;
  }