This took me the entire day to create, but here are your two scripts:
After enabling this switch, all extra study sessions will only consist of vocabulary items with audio => meaning questions. Just like the “Extra Study: Burned Items” script, it might not always work reliably due to a racing condition. For now, I also don’t remove vocab items that don’t have audio.
This script changes the number in the top right of the review/extra study page to an input box which allows you to reduce the queue length. You have to confirm the change with the enter key.