[Evan100]

Stephen – I don’t know if this has changed since your post, but this isn’t great on bbpress 2.5.6, since it also affects the text for the topic subscribe/unsubscribe. Instead of seeing Favorite | Subscribe, you get Favorite (Subscribe). To fix this, you need to post-filter the args, and check before:

function sa_after_get_forum_subscribe_link_parse_args($args) {
   if(empty($args['before'])) {
      $args['before'] = ' (';
      $args['after']  = ')';
   }
   return $args;
}

add_filter(
   'bbp_after_get_forum_subscribe_link_parse_args',
   'sa_after_get_forum_subscribe_link_parse_args');