Hi, it would seem the current maintainer of the Smart Filament Sensor can no longer maintain it. No commits or issues replied to in a year, and they added a note to the very bottom of the readme.md saying "2022: Currently no further development, feel free to continue development in personal forks"
Would it be possible to reach out to the community at large to see if someone else would be able to step up, similar to the notifications we got about the Enclosure plugin? It's a niche plugin, sure, but an extremely useful one for a lot of people who rely on it. The Octoprint plugin listing page for it shows ~600 installs.