Hi... sorry about such a late response. While this seems like a trivial enhancement, there are many unknowns. For example - do these different currency accounts show up while tallying the account balances, do we do any currency conversion, should we just hide transactions that happen in these accounts, etc?
I think the best way would be able to change the default currency in an Account, then not list expenses/income that happen in these accounts when listing all other expenses/income, the transactions here just get listed when you get into the Account. What do you think?