My T calls our relationship reparative, which I think encompasses some of the stuff you talk about in the post. So that seems to be one function of it, like it's a vessel for the work rather than the work itself.
I also think if it's an element of the relationship which emerges, it's really important to deal with aspects of the relationship in the here-and-now, so it is important for that reason too. And for me, like you, there's something about noticing how this relates to my relationship with men more generally.
I do have another thought though, which may resonate, otherwise you are welcome to discard it.
With T1, I had all of these feelings but there were so many blocks to exploring them. T1 wouldn't engage with them in the way that I needed, and I thought when you said today about MC turning the focus to H's feelings when the topic coming up - MC can't engage with your feelings in the way that you need because he is your marriage counsellor, not your therapist.
With T1, I eventually had to say "this is not somewhere I can explore this stuff freely. This is not the appropriate platform" and that's why I found T. And those feelings did resolve themselves as I dove deeply into them with T. I just don't know whether trying to resolve them in marriage counselling is going to ultimately leave you feeling unheard and like your feelings have been marginalised. I know you do discuss it with T but I get the sense you ultimately still want to work through it with MC primarily. Do you see a way forward for that in the context of marriage counselling? Is it possible to develop a strategy for that you can all agree on? If not it seems like you're going to be left feeling repeatedly unsatisfied with MC.