Utf8 Byte Order Marker not working

See https://www.drupal.org/project/csv_serialization/issues/2859030 → . The patch added by this issue enables the inclusion of a BOM at the start of CSV output when the following conditions are met:

$this->useUtf8Bom = ($settings['encoding'] === 'utf8' && !empty($settings['utf8_bom']));

Note the reference to the setting utf8_bom. I cannot find any reference to this setting elsewhere in the csv_serialisation code so it never passes and the BOM is never included.