That is something only the IRS can answer ... there are no rules, regs or precedents to look at ... that said there is nothing you can really do about the 2019 return right now and unless you go to a paid tax pro that can still efile a 2018 return mailing in a 2018 return now will also probably not help in time for the stimulus check ... good news is if you do not get it in advance now you would be eligible when you file the 2020 return.
