Save value of ACF form field to the featured image of the post.

acf-featured-image-workaround.php

<?php

function acf_set_featured_image( $value, $post_id, $field  ){
    
    if($value != '' && 'location' == get_post_type()){
      //Add the value which is the image ID to the _thumbnail_id meta data for the current post
      update_post_meta($post_id, '_thumbnail_id', $value);
    }
 
    return $value;
}


// acf/update_value/name={$field_name} - filter for a specific field based on it's name
add_filter('acf/update_value/name=location_featured_image', 'acf_set_featured_image', 1, 3);

?>