Script collections

https://github.com/pchiorean/Indentz

Release All Anchored Objects

https://github.com/InDesign-Scripts/releaseAnchoredObjects

Automating character style application

see InDD workflow for keeping formatting > What Scripts are included in Style Prep

Optimize links

https://zevrix.com/linkoptimizer/
Another paid option, and arguably not as important given PDFs can have export settings to them that do this for you. But might be useful!

Web Prep

https://www.marspremedia.com/software/indesign/web-prep
Prepares document for ebooks or HTML