Paper

I made a copy of the short year return and was able to clear prior submissions through e-file support tools. It appears that I can e-file as if a new return is being filed for 2020.

You can try, but I bet one of Phoebe's shiny nickels it won't work. Never has for prior years. The efile system will read this short year return as a 2019 return and give the error that a 2019 return has already been filed.