CHUH

I just updated and these options are there now. Thanks!

I just wrote a small plugin that moves all unused files to a trash directory. USE AT OWN RISK. Make sure you edit the *** areas with your own settings.

<?php
/*
Plugin Name: WPDM Dead File Checker
Plugin URI: https://wordpress.org/plugins/wpdm_check
Description: Make a list of valid documents.
Version: 1
Author: Colin T
Author URI: http://maniacalventures.com
License: GPLv2 or later
Text Domain: wpdm_check
*/

$dwhtk = new wpdm_check;

class wpdm_check {
	var $wp_prefix = '****';
	var $file_dir	= '***\wp-content\uploads\download-manager-files';
	var $trash_dir	= '***\wp-content\uploads\download-manager-files-trash';
	function __construct() {
		if( !is_dir( $this->trash_dir ) ) {
			mkdir( $this->trash_dir );
		}
		add_action( 'admin_menu', [ $this, 'activate_page' ] );		
	}
	function doit() {
		global $wpdb;				
		$query = "	SELECT po.ID, pm.meta_value FROM {$this->wp_prefix}_posts po 
					LEFT JOIN {$this->wp_prefix}_postmeta pm ON po.ID = pm.post_id 
					WHERE post_type LIKE 'wpdmpro' and meta_key LIKE '__wpdm_files'";
		$raw = $wpdb->get_results( $query );		
		$valid_list = [];
		foreach( $raw as $val ) {
			$valid_list += unserialize( $val->meta_value );
		}
		sort( $valid_list );		
		$real_list = [];		
		foreach( scandir( $this->file_dir ) as $val ) {
			if( $val == '.' or  $val == '..' ) continue;
			$real_list[] = $val;
		}
		$difference = array_diff( $real_list, $valid_list );		
		foreach( $difference as $val ) {
			echo "Trashing: ".$val."<br>\r\n";
			rename( $this->file_dir .'\\'. $val, $this->trash_dir.'\\'.$val );
		}		
	}	
	function activate_page() {
		add_menu_page( 'WPDM Check', 'WPDM Check', 'read', 'wpdm_check_management',  [ $this, 'doit' ], '', 200 );
	}
}