Amending to remove dependent

If an amendment to remove a dependent who was accidentally   claimed  is electronically filed how long until the irs has the dependent’s ss # cleared in their system so the person who should claim the dependent can file?

can the person who should claim the dependent file an extension to wait out the process instead of manually file? 
Or if they did manually file, Would it make sense to send a letter along  explaining that amendment to remove the dependent  has been electronically filed by so and so, so they know it’s in process? 
Last question, does TurboTax allow you to electronically refund return $ in an amendment or is a check needed?