We recently started using Nextcloud Deck, Nextcloud’s kanban-style task-tracking app to track production of the LibreOffice User Guides, as a replacement for the old spreadsheet system.
I’ve created wiki page explaining how to use Deck for tracking User Guide production, including how to access the app, here:
Managing Guide Production Tasks with Nextcloud Deck
Please take a look if you are working on the User Guides, and don’t hesitate to ask for assistance in the forums, mailing list, or the LibreOffice Documentation Telegram channel if you need help with Deck.