In Budgets and Forecasts, you can use the Reference Only tab with multiple measures (driver-based budgeting) to convert the budgeted local currency value to a reporting currency value.
The advantage of this method has over option 2 is that the currency conversion happens in real time as local currency values are entered, and by publishing the reference tab both the local and reporting currency values appear in the budget stream in Financial Statements. Note however that there are some limitations of this approach. Firstly, this approach does not support 3-statement budgeting, and secondly, any GL accounts or entities added to the main tab would also need to be added to the second tab . We are investigating changes we could make to address these limitations.