I would be happy to have it in my client. If I could have a personal list of tagged users so that their names showed up in a different color I wouldn't accidentally get drawn into a conversation with someone who is just using childish, circular arguments and utter nonsense in a bad faith attempt to derail the conversation. I could just ignore them and continue the discussion with other users but I could also warn others who were engaging with them and becoming frustrated that they are bad actors and that they are wasting their breath.