Seems like ProConnect does not support efiling a Superseding 1120S. So you might be better off just amend, and efile. See link:

https://proconnect.intuit.com/community/proconnect-tax-discussions/discussion/how-do-i-mark-an-s-cor...

Or Print and Mail it.

The idea is to avoid having to mail it. Never been a better time to avoid that in my opinion. There is software that offers a Superseding Return button and the IRS references the ability to do this as well. Seems like a fairly easy option to include as part of ProConnect. Not a lot of demand for it I'm sure but I would still expect to see it.

Agree. I don't think any of Intuit's professional tax software - Lacerte, ProSeries or PTO - offer this.