I often felt disproportional rage at my first therapist towards the end but it was always triggered by something he said or did. He would explain it as a transference reaction, being originally angry at my mother, and I think there was something in that as he did remind me of my mom in some (negative) ways while often said he was trying to provide nurture I did not get from her (which I thought ridiculously simplistic and superficial). But I think it was often displaced anger and frustration about myself projected onto him, that I felt I was running in circles and got worse rather than better. Was also frustrated that he did not or could not help me with a major issue I had. According to his therapeutic approach, feeling and expressing intense anger toward the therapist should be very beneficial as an expression of frustration we normally turn inward or repress. I did not find it very helpful, it more destroyed the therapy to fight and not address "the elephant in the room". I do believe though it can be helpful for someone who has a lot of unprocessed anger and frustration or tend to be excessively self-deprecating without an apparent reason.

Never felt anything like that toward my second therapist, not even normal anger except some very fleeting and mild form maybe twice.

I would probably try to identify triggers of the anger if simply expressing it is not helpful enough. I imagine there are triggers that initiate it even if the reaction itself feels out of proportion or inappropriate.