When creating a smart query definition you can only use one currency field.  It would be really beneficial to be able to create outputs like Total Amount, Average Amount, Largest Gift.  in the same smart query, but right now it auto generates the currency ID as the same name and it won't allow multiple columns with the same name.  Simple adjusting these to alias as 1-2-3 etc should fix this option, but this can't be done by the user on these background columns.