Updating Pricing Precision to -4 Decimals positions.

What are the impacts of updating your price precision from -2 decimals to -4 decimals.  This is a global site with more than 10 Global currencies (EUR, GBP, INR, AUD, SGD, BRL, MXN, ann others.  This install is 5 years of E-Business Suite Data with multiple operating units.  Current rounding for many currencies is -2 decimals but want to investigate going to -4 if possible.  I want to understand the financial, business, technological impacts.  This E-Business environment includes Latin America Localization, VAT, APAC GST, and India GST.  Would appreciate inputs on when should a change occur - Beginning of physical year.