From what I've read on here and my own experiences, I think it's mostly about the T and how comfortable they are dealing with transference.

Like my marriage counselor seems quite comfortable with it (and even thinks transference can be helpful to the therapy), so we (me, H, and MC) have been able to continue working together and also work on/through my transference issues. My individual T has been a little weird at times regarding my (much less intense) maternal transference for her. I think if my transference for her was as intense as mine for MC, then I don't know how well our therapy would be working. (There are still issues with her from time to time that I think are mostly from transference/countertransference.)

It's hard to say how your regular T would respond. But from what the new T you contacted said, maybe *she* wouldn't be comfortable dealing with transference? If she said the thing about how you shouldn't keep seeing a T. Did you ask her for more clarification of that?