@sjrcpa - The National Taxpayer Advocate had an article on their site about Superseding returns last year in April. It must be deleted now but thankfully Wayback Machine has archived it for us: https://web.archive.org/web/20201019010552/https://taxpayeradvocate.irs.gov/news/NTA_Blog_The_Value_...

Here was a post by Spidell a year ago stating that for business entities, the superseded return may be e-filed by checking the superseding return box on the electronic submission. For individuals, the process takes longer. Superseding individual returns (Forms 1040) must be filed on paper and mailed to an IRS processing center where they are subject to processing delays and a greater risk of transcription errors. Here is a link to their email/post: https://www.magnetmail.net/actions/email_web_version.cfm?ep=BWwNB7MNTsGioBV5xN_a_UzEqWoTvYQFzM7ro2DiK...