Bigcommerce API PHP library will not create a customer with custom form_fields

I'm using the Bigcommerce php library to create customers through the API, which works fine, but I get {"status":400,"message":"The field 'name' is invalid."} back when I try adding the form_fields array of objects to the call. Is it possible to include these in a createCustomer call?

Here's basically what I'm trying to do:

$customer_object = array(
    "email" => $email,
    "first_name" => $first_name,
    "last_name" => $last_name,
    "_authentication" => array(
        "password" => $password
    )
);
$form_fields = array();
if(!empty($occupation)) {
    $obj = (object) array("name" => "Occupation", "value" => $occupation);
    array_push($form_fields, $obj);
}
$customer_object["form_fields"] = $form_fields;
$response = Bigcommerce::createCustomer(json_encode($customer_object));

Also, here's what a Bigcommerce customer record looks like:

Bigcommerce\Api\Resources\Customer Object
(
    [ignoreOnCreate:protected] => Array
        (
            [0] => id
        )

    [ignoreOnUpdate:protected] => Array
        (
            [0] => id
        )

    [fields:protected] => stdClass Object
        (
            [id] => 34
            [company] => Company Name
            [first_name] => John
            [last_name] => doe
            [email] => email@example.com
            [phone] => 123-456-7890
            [date_created] => Tue, 19 Jul 2016 23:40:14 +0000
            [date_modified] => Wed, 10 Aug 2016 17:39:28 +0000
            [store_credit] => 0.0000
            [registration_ip_address] => 
            [customer_group_id] => 6
            [notes] => 
            [tax_exempt_category] => 
            [reset_pass_on_login] => 
            [accepts_marketing] => 
            [addresses] => stdClass Object
                (
                    [url] => https://example.com/api/v2/customers/34/addresses.json
                    [resource] => /customers/34/addresses
                )

            [form_fields] => Array
                (
                    [0] => stdClass Object
                        (
                            [name] => Occupation
                            [value] => Developer
                        )
                )

        )

    [id:protected] => 34
    [ignoreIfZero:protected] => Array
        (
        )

    [fieldMap:protected] => Array
        (
        )

)

Form_fields are currently GET only and they are only available in stores with a specific "store experiment" turned on. This has been omitted from our documentation, so we will work on updating that to provide better clarity.