I see “just” as an invitation to win the argument by agreeing with the person. “Ooo yeah good idea, I think we could. Can you help me think through this?” — And

I see “just” as an invitation to win the argument by agreeing with the person. “Ooo yeah good idea, I think we could. Can you help me think through this?” — And then they ideally proceed to come around to essentially what you wanted to do anyways.