I seem to remember that we were aware that fractional commodities were going away, but exact rational values would still be important to be able to represent historical holdings and transactions.
The current value of held assets in another currency isn't really "counting" any more, it's a prediction of the outcome of some future transaction that hasn't happened. So I'm less concerned about exactly computing it than I am in never making a mistake in assets that I am counting, i.e. keeping in one account and only incrementing and decrementing the amount when a transaction occurs.