I don't know. Hate to be the negative one, but this brings up a bad experience for me regarding crossed boundaries.
I had a therapist for a few years. Now that I think back, she talked a little too much about herself sometimes...not sure what she was trying to get across, possibly harmless.
Then she got sick with Parkinson's and closed her practice. Called me to her house and said in her thirty years of practice, my life was about the worse she'd heard. then she gave me her mother's wedding ring because she thought I was going to get married. I was appreciative and touched, but it came with the clause of not telling my other therapist cause it was against the rules.
then, after several months of this guy not proposing, she called me several times asking if I'd done anything with the ring. I said, what? am I supposed to force him into proposing? If you want the ring back, just say so.
She said that the gift meant alot to her and wanted to make sure it was being used properly.
We did eventually get married and used the diamond from the ring. But after that it was ruined, didn't even want to use it, felt like the several 'weird' phone calls after our therapy was done was like talking to my guilt tripping mother.......really did some damage. I wanted to sever the relationship after her practice was over and move on, but she called and called. It was too weird for me and I told her several times, yet she continued to call.
Told this to several other Ts and they were literally shocked and felt bad for me. I felt violated, manipulated and guilt tripped over the edge. Really bad.
So there's my two cents about getting emotionally involved with a T. No harm in telling or showing them you appreciate their work, but on a personal level, I'd say that's a no no.