Exchange rate significant figures

Any chance of increasing the number of significant figures used for exchange rates from five to six?

The current number of significant figures leads to (small) rounding errors between the calculated and actual converted amounts for large sums. e.g. US$4,461.80 @ 1.3238 = £3,370.45 . The actual amount should be £3,370.50. That equates to an exchange rate of 1.32378 to 6 s.f (or, better, 0.755413, since we’re converting from USD to GBP).