I am currently doing the same. Reusing the nic and just change addressType and macAddress properties but I get the following fault:
Fatal error: Uncaught exception 'Vmwarephp\Exception\Soap' with message 'ServerFaultCode: . InvalidProperty: InvalidProperty Object
{
[name] => _
}
' in /var/www/html/Vmwarephp/Service.php:74
I cannot find which property is generating the error. The "_" is only available in ManagedObjectReference object which are untouched in my code.