In a cooperative argument, you should never* explicitly refer to logical fallacies.
*additional qualifications below
This is a point I’ve made several times before, especially in my How To Argue post.
In that post, I make a distinction between cooperative and competitive arguments. In a cooperative argument, you are trying to find the truth, which involves coming up with the best arguments you can, but does not necessarily involve “winning” the argument. In a competitive argument, you are trying to win the argument, which might involve coming up with truthful arguments, but not necessarily. I don’t mean to say there is anything inherently wrong with having a competitive argument, I’m just not talking about them here.
In a cooperative argument, you don’t want to antagonize the person you are arguing with (“interlocutor” is the term I would use). After all, your goals are aligned. You’re both trying to figure out the truth. And if you tell your interlocutor that they’ve just used a logical fallacy, I think there’s something inherently antagonizing about that. It’s like telling them not just that they’re wrong, but that they’re wrong in a particularly predictable and trite way.