This code snippet disables the map marker clustering in the User Locations extension.

um_member_directory_disable_clustering.php

<?php

/**
 * Disable Clustering
 */
add_action( 'wp_footer', function () {
  ?><script type="text/javascript">
    wp.hooks.addFilter( 'um_member_directory_disable_clustering', 'um_user_locations', function ( disableClustering, directory ) {
      disableClustering = true;
      return disableClustering;
    }, 20 );
  </script><?php
}, 20 );

This gist is a part of the article User Locations - Hooks

You can add this code to the functions.php file in the active theme directory. Skip the opening <?php tag.