Ah .. I see, advance embed code do not recognize "$_REQUEST['id']" code indeed. You need to determine what is your form id with custom code. To do so, you can use a session variable, you already have advance embed code like this :
<?php
require("C:/path/machform.php");
$mf_param['form_id'] = 1;
$mf_param['base_path'] = 'http://yourdomain.com/machform/';
display_machform($mf_param);
?>
then, add a session variable to be like this
<?php
require("C:/path/machform.php");
$mf_param['form_id'] = 1;
$_SESSION['sess_form_id'] = 1;
$mf_param['base_path'] = 'http://yourdomain.com/machform/';
display_machform($mf_param);
?>
after that, add an "or" condition to your "view-function.php" like this
if(($_REQUEST['id'] == 1 || $_SESSION['sess_form_id'] == 1 ) && ($element->id == 3)){
$element->default_value = $_SESSION['your_session_var'];
}
MachForm Support