I spoke to customer support. We spent 1.5 hours trying different options and still could not get Turbotax to stop creating a Form 8888 for my amended return. They transferred me to a tax specialist who told me to swap the primary and secondary taxpayers (the primary had passed away last year), and swap the data entered for anything specific to each taxpayer, i.e. the 1099R forms. I did all that and it created an error because the taxpayer IDs can't be changed on an amended return from what was submitted on the original e-filed return. It looks like I'm forced to paper mail the return.
