In many previous tickets (e.g. https://eventespresso.com/topic/state-sales-tax/)
you helped clear the tax decimals by adding a third decimal.
BUT
It creates a real bad situation whereas the customer sees a price ticket with three decimals. It makes no sense.
Why don’t you keep the ability to have 3 decimals BUT showing rounded pricing with two decimals only – like any other software.
It is easy (it is a basic function found everywhere) whereas the decimal is rounded down when it shows x.xx4 and less or rounded up when it shows x.xx5 and more.