The payment token value gets stored under the mastercard_payment_token attribute on the order level. Below is an example of an API response of an order where you can see the stored token value.
ACH will not support the VATO payment option as it does not allow capturing the amount.
Instead of Username and Password, an SSL certificate can be used. When this option is selected under Authentication Type, the admin panel will need to submit the following information:
In the Advanced configuration section, you can find information about the current API version utilized by the Mastercard Payment gateway plugin.