How to deal with a user who produced a steady stream of valuable answers, but tends to generate a large number of arguments/flags from comments
This is a question taken from 2018 Moderator Election Q&A - Questionnaire.
Since there is a moderator election in progress, answering this, could serve as inspiration for the candidates.
Let's let the candidates express their own opinion about this topic.
But to answer this in general, each user (that is not a moderator) and finds such behavior should flag one of the posts of the user in question and explain the problem.
A moderator will handle the flag.