Hi Sander,
Currently, we do not support retrieve and modify the custom metadata from the PDF document in flutter PDF library. However, we have added it to our feature request list. While we don’t have immediate plans to implement it, we typically review all open feature requests during the planning phase of each release cycle, which occurs approximately every three months. We will consider this feature for future implementation and provide updates once it becomes available.
You can track the status of this feature request from the following feedback link,
https://www.syncfusion.com/feedback/65684/support-to-retrieve-and-modify-the-custom-metadata-from-the-pdf-document
Regards,
Irfana J.