I notice that often (not always) inflammatory comments are written by those who frequent politics related communities.
In addition to being straight up antagonistic, the comments often are about labeling and categorizing everything.
Like if someone posted a meme or made a joke. It can't just simply be taken at face value. The commenter is compelled
to categorize it, label it, assume there is an underlying agenda. It has to be Russian or Chinese propaganda, it's far-left or far right,
its LGBTQ related, it's incel related, it's promoting some agenda somehow.
When I go to check their profile it is very common that the individual frequently comments in politics related communities.
Man, not everything on the planet needs to be politics related. There's not a deep state agenda for everything.
Memes and jokes are sometimes dumb and silly and no one is trying to promote anything. There is actually a type of humor
called Surreal humor or Absurdist humor which like sarcasm seems like a lot
of people just don't get.
You're basically asking "do you check for red flags on everybody who is not raising red flags?"
In comment threads, I usually only check post history for people I am considering blocking. It makes sense to check post history if people are instigating. If that person is just starting shit everywhere then there's no reason to listen to them, but if they have a history of reasoned discussion then maybe what they say is worth considering. (I realize how ironic this is coming from somebody who has almost no comment history on a new account)
Yes, this is the "base rate" fallacy. You may find the "red flags" your looking for, but they may actually be more common among other commenters that you don't examine.
Simply, what is the "base rate" of those red flags on average? You have to examine a random sample of commenters to know that.