Exchange Rate Object

I have been looking through the API docs and noticed there is an "exchangerate" object. However, in both Stitch and Fivetran documentation for QuickBooks connectors I do not see an exchangerate table? I know exchange rate is only recorded in your QB profile if you elect to record more than one currency. I am working with data right now that is only on one currency; however, as it seems we will expand and have transactions in another currency I want to be prepared if I will be able to reference an exchangerate object for exchange rates? Or will I need to get all exchange rate information via the transaction tables (journal entry, bill, sales receipt, etc.)? 

Also on this topic of exchange rates, are they updated each day to reflect the current exchange rate between the currencies or is it static for the date of the transaction? For example, if a transaction occurred in EUR in April, will the exchange rate to USD listed in the table stay the same, or will it update each day for the accurate exchange rate? As the exchange rate in April will be different than when we report in December.

Any help is appreciated! Or if I missed a previous discussion on this topic it would be appreciated if you could direct me there.