We have removed #RSSGuard from our list of recommended software.
Its JavaScript article filters are the USP for RSS Guard, because they're so much more powerful than the filtering by search words or regular expressions available in other feed reader applications.
Migration from 4.8.6 to version 5 is only mostly seamless for local accounts. Still, you lose your assignments of article filters to the specific RSS feeds you want them applied to.
Users of Nextcloud News are losing their article filters, completely.
I'm happy that I was succesful in convincing both the maintainers of Akregator and RSSGuard to add support for the "feed:" protocol to their apps. This helps websites providing links for feeds that really end up in the feed reader a Linux user has installed.