Report transformations in the past imported tax codes, custom fields and COA changes, making them a powerful customization tool.
The new implementation has a batch update of report transformations which I hoped implemented the same functionality.
I just tested it my self and unfortunately batch update of report transformation are much more limited, currently really only being useful to copy the spreadsheet layout portion of the localisation. I couldn’t see the “Script” portion of the report transformation, nor custom fields, tax codes, etc
So unfortunately report transformation batch update can not be used to copy tax codes. The best you can do is start from a template business.