Cost Flow Methods

We have a std costing system.  Our receipt cost method and deplete cost method is set at std. cost.  Our non lot controlled items are set at receipt cost flow of FIFO.  Our lot controlled items are set at receipt cost flow of Lot ID.  Is there any good reason to have lot items set at Lot ID if you are using std. costs?  Does having it set at Lot ID impede the performance of the cost accounting creation job?C