I used https://github.com/ToneyAlexander/HackerTagger for a bit almost a decade ago. Data locally stored, good but didn't transfer across machines, not so great.

It had a little text label next to names so you could manually add whatever you want. Recently I've thought about this extension and using it to tag the LLM users, or the humans who tend to pop up to fan the flames or who regularly post thought terminating comments - little tags to remind me to ignore the bots and trolls.