When we do get the update within TurboTax (est 3/18) it should be super easy for it to do the basic calculations, as the manual 1040-X form is really that easy too.
E-filing it will speed things up all the way around, but if as in my case, I will owe more than originally e-filed, there's really no pressing need to e-file it since we have until April 15th to amend with zero penalty, just as-if it were our original return being mailed on that date.
My personal experience with the USPS is that you need certified mail and return receipt else in 12 years of me mailing (prior to e-filing ability), twice I didn't use that and twice they claimed not to receive it, however knew my exact to the penny tax which would have required them to know what was on my Schedule A in those returns (e.g., Charitable donations) so had to argue that with the IRS to not pay late filing/late payment fees successfully.
To another point: will state amendments also be readied for 1040-X timing? Different states use different form names for amendments.
