I am not a tax advisor, just a TT user suffering from the same mess all are talking about in this thread. I will say that please send the additional documents by mail to IRS. Include a letter mentioning that you e-filed via turbo tax and later discovered that IRS might need these supporting documents. Then tender an apology for the inconvenience.
If IRS still needs more documents, they will probably ask for it.
Last year, IRS sent me a letter around end of summer stating that I have to pay additional couple of hundred dollars. I just paid it via the IRS website as soon as I read the letter. Somehow Turbo Tax miscalculated things, or maybe I did not understand some of the questions Turbo Tax asked during my tax preparation. Either way, IRS just asked to pay the additional amount as IRS calculated it; there was no audit or any other complexity.
All I am saying is, I try to pay the correct amount of taxes. I do not have any intention of hiding my income from IRS. So, no worries. If IRS finds errors, they will inform me. (Probably I am saying a dumb thing but hey, isn’t life already complex enough?)
Again, this was not a tax-related advise. I just mentioned what I would do.
