Pay for reservation in TNEW

Hi,

Is anyone else using a customisation in TNEW to allow customers to pay off reservations? We have one in V15 and are wondering if there are any alternatives in V16 that people are already using?
Our current customisation works by inserting a link in the order confirmation for any unpaid orders. The link fires a local procedure in TNEW that populates the cart with values from the order (event description, number of tickets, price types and £ values). The customer then checks out that cart and the payment is offset by an On Account balance. We then use that balance to pay off the original order.
Before we commit to paying for this to be re-built in V16, we'd be interested to know if there any similar processes being used in V16?

Thanks

Brian