https://proconnect.intuit.com/community/electronic-filing/help/how-to-lock-and-unlock-returns-in-pro...

You may want to wait until it is accepted. If it is rejected, then unlocking and changing will impact how the agencies see it. If it is accepted with the mispell then unlocking and changing will make it right in future.  The clients didn't notice when they signed the 8879?