Hello!
I’m not really sure what you mean by “files in a reserved area”.
By default, the media files attached as children to all posts, pages, and custom post types are removed automatically.
For specialized needs, you can use a filter to overwrite this behavior and define custom rules for removing your attachments. There is a code snippet in the FAQ section of the plugin you can modify to your needs. (the example shows how you can limit the removal of child attachments to specific post types)
Keep in mind, the filter applies rules to the parent, not individual child attachments.
