"Fast" is a 3rd party extension we've seen some clients use to accelerate the checkout process for their customers. In this article, we'll discuss why we do not recommend clients use the "Fast" extension.
Not Using Fast
"Fast" works in part by altering how payment records are sent from BigCommerce. These payment records are, in fact, sent back to us as completely empty, which makes it impossible for us to send those orders down to your POS/ERP system.
While it is unlikely that we add supporting "Fast" to our development slate in the near future, if this is a major concern for you please let us know with a support request from the Modern Retail Admin Panel.