I have exactly the same problem as you do, and it is frustrating. I use the Tax Transactions report. My USD customers all have “ (USD)” at the end of their names, so it’s easy to identify those transactions in the report. Your use of separate tax codes for each currency will make it even easier, but when I installed my fiscal device I had to revert to using a single tax code for all 14.5% VAT transactions. I copy the report into a spreadsheet application, split the ZWL and USD customers into separate columns, and add another column for the exchange rate which I use to convert the USD transactions back to USD amounts. I’m sure someone more skilled with spreadsheets could automate this to a degree. For the number of transactions I’m dealing with this is workable, but your situation may be different.
You may find this topic relevant: VAT report by currency I gave up on the report transformation, as it was taking a lot of time for me to figure out, and I didn’t have full confidence that I was extracting the correct data. Hopefully I can revisit it at some point, as it would be great to have a one-click report available for VAT returns.