exchange rate date update at contract header

Summary:

we have an RMCS Contract created with future start date. RMCS is considering the start date of the obligation line as the contract date and exchange rate date. due to this the contract is not getting allocated with error "Exchange rate not available".

can we perform FBDI correction on header/line to update the exchange rate date to get the rates as per today's rate?

this contract has other Quantity based lines with Immediate Accounting rule which are already satisfied. but due to the amortization lines exchange rate error, the overall contract is in Allocation error and we are missing revenue.