IRS says wait.....If the refund is a large one, I might consider amending.  BUT, an amended return isn't processed for 6-8 months so I'm not sure that would be faster.

If more is owed (I've had one that owes more), I might consider amending so that the balance can get paid. I *suspect* the IRS will waive any interest/penalties on those balances - but who knows ?