I think what you're referring to here ^ is "healthy" shame; but your previous posts describe very unhealthy shame. An awareness of, but not being motivated by, shame is healthy, and is a precursor to empathic capacity (why sociopaths lack capacity for both shame and empathy.). But the sort of shame elicited by negative comparisons is not healthy shame, and people experiencing such shame often cannot extend empathy to others. Sometimes, with difficulty, they can accept empathy from others.

I think this is the fallacy behind thinking a T who shares a client's issue will understand and so empathize better for having shared the experience: if the T has truly processed the issue, it's possible. But if the T has not truly processed the issue, the attached unhealthy shame will hinder the ability to empathize.

And, no, I haven't specifically researched shame as it is not my field, but that doesn't prevent me from knowing my own experience of therapy and life.