My impression is that working with transference is not only about discussing the there and then but also the here and now - which can involve therapist disclosures of their reactions to your transference (whether you want to classify this as countertransference or not). I do think insight based on the past can be helpful, but only if it's applied to the present. Otherwise, what's the point?

I think you've said many times when you have a reaction that it's not really about him, it's about something in your past. I would try reframing this as it's about you and the way you see and relate to things. Because just saying it's about the past seems to minimize that whatever dynamic happened then is something that is being reenacted in the here and now.