If you really never use the built-in screenshot functionality in Firefox, you can disable it by setting `screenshots.browser.component.enabled` to `false` in about:config. That will also remove the context menu item.
This is bug 1643719. You can see in the screenshot that the scrollable area is the main/bottom-right region of the page - the page itself is not scrollable. So we would need to guess which part of the page to scroll and how to assemble a single image...
The issue with the PDF viewer is another instance of 2 much-reported and duplicated bugs:
https://bugzilla.mozilla.org/show_bug.cgi?id=1643719
https://bugzilla.mozilla.org/show_bug.cgi?id=1646063
Its somewhat complicated and there isn't an obvious s...
We have something like this planned and on file at Bug 1873249 - Include list of session backups on the about:sessionrestore page. Does that sound like it would cover it?
Yeah we've encountered this problem before, and there's a similar bug on file at https://bugzilla.mozilla.org/show_bug.cgi?id=1896019.
Your suggestions make sense and would be worth prototyping to see how they pan out. The workaround of course is to ...