Not sure if this is of any help, but I found this information in the article “Small steps and a big leap - First pre-release of Android 11 and new features for pixel phones released” on page 42 of issue 07/2020 of the German computer magazine c’t:
“The Scoped Storage introduced with Android 10 has been improved in terms of security and privacy. The sandbox principle of the internal memory is extended to the shared memory or SD card: apps can no longer access any data there either. The API innovations suggest that for extended access, an app must first request the necessary authorization from the user.”
Translated from German by deepl.com