I think I figured it out. For each of the years 2014,2015,2016 I removed the state tax refund amount from the State and Local Tax Worksheet, edited Schedule A to reflect the actual state withholding from the w2 in the tax year (instead of a cumulative amount of the previous refunds and the w2 amount) and also removed the Estimated Payments. This adjusted my AGI lower as well as adjusting my Itemized Deductions lower by the amount of the state taxes received in the previous years. This means my AGI changed but not my Taxable income or my tax liability. I may not even need to file amended returns since my tax liability did not change. Once I do 2017 taxes, I will have to report the 4 years (2013-2016) of refunds on Line 10. If you want to support filing older taxes in a year later than the following year, the import feature should check the year the refunds were received instead of assuming it is received in the immediate following year. As far as I can tell, the program would be able to handle everything by verifying when the state refunds were received.
