facetwp sort ACF taxonomy relationship fields by term order of the tax

<?php
/**
 * order facets by term order
 * note: facets are an ACF relationship field
 * rather than a direct taxonomy field which
 * prevents use of taxomomy order directly with get_terms_orderby
 */
add_filter( 'facetwp_facet_orderby', function( $orderby, $facet ) {
	// use 'facet_name' => 'taxonomy slug'
	$ordered_facets = [
		'facet_one' => 'tax_one',
		'facet_two' => 'tax_two'
	];
	if (  $ordered_facets[$facet['name']] ) {		
		$terms = get_terms( array(
			'taxonomy' => $ordered_facets[$facet['name']],
    		'hide_empty' => false,
			'orderby' => 'term_order',
			'order' => 'ASC'
		));
		foreach ($terms AS $term ) {
			$termlist[] = $term->slug;
		}
        $orderby = 'FIELD(f.facet_value, "' . implode( '", "', $termlist ) . '" )';
    }
    return $orderby;
}, 11, 2);