Question regarding Funding Revaluation

We have a few projects that have different functional and project currencies and we are not currently running a funding revaluation process.  I'm looking for some feedback on the best practice on adding funding revaluation to our processes.  If we were to start running this would it be the best practice to run for project for each closing period from the time the project started through present or would it be best just to run as of the current closing period?

If it is run for each closing period from the project opening through present can one adjustment be made to the budget for the total affect for all periods or does it have to be baselined after each revaluation process is run?