Thanks, what you're seeing is a limitation that we have for performance reasons when a PDF contains too many pages.
We might be able to lift this limitation after we implement a few optimizations for cases like this.
We have been working on multiple improvements to the page, and we have also made it accessible through a Quick Action in the address bar: e.g. just type "tra" and you will see a button that will bring you to the page if you click on it.We are hoping ...
@Valentin93 this is actually already available today, you can click on the comment icon in the toolbar (top right) to view the sidebar with the comments!See the "Useful Tips" section under "Comment in PDF files" on https://support.mozilla.org/kb/view...
