Provide a way for users to edit annotation URLs

I created several annotations on a PDF hosted at a URL that was subsequently taken down. I can find the annotations via Activity Pages, but annotation sharing links no longer work. I have been able to find an updated URL for the PDF, and thanks to PDF fingerprints, my annotations do show when the extension is activated on the new URL. However it would be helpful if I could edit the annotations from the sidebar or notebook UI to replace their existing URL.