How to add Bill Credit Details to the EFT Payment Email Notifications?

Hi,

I've been looking for ways to add bill credits to our eft_vendor_payment template.

We can see bill credits in a sublist in the vendor payment transaction (bill payment) but it's not there in edit mode.

If I load the transaction using suitescript it's not there either, only bills show up in the "apply" sublist.

Diving a bit deeper I've found the code to send emails in the EFT Module (8859_EmailNotificationRenderer.js). I can see that the payment record is loaded and injected into the template.

var paymentRecord = record.load({
    id: notification.id,
    type: notification.recordType
});

Is it possible to override this file and add my own code to be executed during the map / reduce? All the files are locked on my end.