For making beauty modifiers that require a basis-shape as reference (e.g. corrective smooth) use a whole animation instead of one shape as their basis. More details on how to use are in the script itself.
If you use my SACS script, I recommend using the RB on your result. Visit https://www.deviantart.com/cardboy0 if you want to see more things by me or message me on https://twitter.com/cardboy0 .
For older versions, go to https://github.com/Cardboy0/retroactive-beautifier/tree/old-versions .
If you intend to analyse this script for whatever reason, I included a flowchart (.drawio). You can open it using the site https://app.diagrams.net/ .