since I am in airport nothing I can do . So I just share .
why do I said this ?
in the past QV demo allow user select what currency you want to view. Thru button action. And you can use what if dimension select to achieve display multiple currency in your report..
Because in QS it does not support ColumnDim , in case you use it your expression cannot directly use in QS.
just use in line load create a Rate field and make all currency in single currency.
Now QS have extension on action but only allow 2 action , so it is no enough , further more in QS the design is mean user don't need to click any thing and can read the report.
ALso if using extension it is not support by Cloud access .
in case you are disagree with me , kindly send me your comment.