@Wicket - appreciate the thought. Yes, you are probably right they want that downgraded as well.

This is sort of a separate question which already has some discussion...but

The issue with presentations.currentonly is that my Add-On uses a template (a public one on my drive) for some preconfigured pie wedge shapes with varying start and sweep angles. These are copied and pasted into the users presentation via script, since it is not currently possible to adjust those angels with the API via apps script.

The only way to directly copy shapes is with SlidesApp.openById(...) which requires the full read/write presentations scope. Even using readonly with the advanced Slides API returns a JSON object of the shapes but the angles I mentioned are not included.

The API is very limited for some things.