Yeah, Anja, if it were me I'd likely still opt for the surgery, as there really is no down side I can think of. The only down side they mentioned was potentially not getting the pitch increase you're looking for, however, that's the case no matter what anyways. If that's the only potential side effect then I see no reason you can't still opt for the surgery and hope for the best. As you can see, Dr. Kim does great work, and seeing as how he's a voice surgeon in general along with doing voice feminization surgery I can't think of anyone better to take that risk with.
Yeah, it's a lot of money to risk getting no change, or minimal change, but with the results I'm hearing from them it seems worth it to me. Anyways, it's up to you, but don't give up. Keep practicing your voice with the voice therapist and keep putting that money into savings and if you do decide to go for it then you'll be all set 🙂