You can set the priority of exchange rate providers for obtaining exchange rates for each currency pair. This may help to prevent exceeding request limits to exchange rate providers.
Navigate to Currencies > Currency pairs and select a currency pair for which you want to set the priority of exchange rate providers.
To open the Edit currency pair screen, click the Edit button located in the selected currency pair row.
In the Rates Custom Priority field, drag and drop the exchange rate providers supported for this currency pair to set them in a desired order.
Click Save to apply the changes.