Migration option "idlist-delimiter" cannot be overriden even though documentation says so

When using drush migrate-import command, --idlist-delimiter option should override default delimiter ":" for records.
This is currently not working as this option is never called in the command implementation:

See migrate_tools.drush.inc file, line 159:

foreach (['limit', 'feedback', 'idlist', 'update', 'force'] as $option) {
  if (drush_get_option($option)) {
    $options[$option] = drush_get_option($option);
  }
}