This software really sets itself apart from others by being completely customizable in so many ways, I really appreciate all the hard work of the development team!

Is there anything written up yet about the variables that can be used in email templates? Specifically would like to know the difference between:

$amount

$total

$balance

I am trying to figure out if one of these can be used to show the total amount due, after a late fee has been applied (eg. …your new balance is $total)?

from what i have found. $Balance is the amount unpaid by that customer. so the total outstanding by that customer.
$Amount is the invoice amount so the total invoice.
As for $Total i have not found that in all my JSON mapping.

Is there any variable for the original invoice amount (ie. does not include fees added later)? For example, let’s say an invoice was issued for $100, then a $5 late payment fee was added later. Is there a way to show this in an email template like so:

Invoice Number: 001
Invoice Amount: $100
Due Date: Jan 1, 2019
Balance Due: $105

Right now the totals are all updated with the new amount due, so none reflect the original invoice amount.