Longshot, I know, but there's a wealth of knowledge here.
I've been using Page Saver from Pearl Crescent to take screen dumps of webpages for a while and been very happy with it. You can click and save from the menu the add-in provides inside Firefox. Info:
However, old XUL/XPCOM add-ons have stopped stop working with Firefox, and Firefox probably won't be continuing command line capabilities to their WebExtensions implementation. Firefox announced their decision to stop supporting XUL based addons:
Firefox has a really nice --screenshot command in its Developper Tools (which would be great as it's an internal Firefox command) but I couldn't find a way of automating/scheduling it, nor calling it from a batch file.
I'd really like something for Firefox where one can automate/schedule copies of a specified url (unattended), preferably using Firefox so it grabs the whole page and not just the visible window etc. Any thoughts/suggestions?
TIA