Change in Documentation and Accounting Rule, should we change in DAR or create new DAR and use it?

Summary:

Change in Documentation and Accounting Rule, should we change in DAR or create new DAR and use it?

We tried the following:

1. Change the Exchange Rate in existing DAR Rules tagged to SCFO Flows, system picks up the new Exchange rate.
2. We created new DAR rule with different Exchange rate and used this DAR Rule in the existing SCFO Flow by backdating the Creation date, system allows the same and SCFO flow picked up the new Exchange rate.

We want to confirm that what should be our approach as we have more than 800+ SCFO Flows and want to align with the recommended Oracle Practice, Should we use approach 1 or approach 2 or should we create the SCFO Flows again from scratch with new DAR Rule.