I'm posting this here, too, since I'm a Kim prospect and it has to do with the vocal break matter, which may interest others:
Dr. Kim notes my reading voice pattern to be moderately unstable: pitch instability, and a breathy voice with too much air escaping. Apparently it's the act of defying the way the voice wants to sound on its own that induces voice tremor - that going from chest voice to falsetto makes the voice break more pronounced. They assume the voice break will continue after VFS, but that with botox + if I adapt to my new vocal folds, the voice break is believed to improve.
This really seems to support the notion that it's our voice box musculature being used to working with thick, long vocal folds which causes tremor, and that it's not necessarily something innate or permanent. If this is the case, I feel a lot better about having VFS done, as the vocal break matter is one of the last things I've been concerned about. Truth be told, I actually 'can' cross that break, but because my voice is so breathy, there's a super-fine line between clocking the break and using not enough air to induce vibration. And that's almost certainly due to my voice feminization techniques.
As for the simple presence of tremor, I can reflect that in my first year or two post-transition, I had a good friend (choral expert) who noted one of my strengths was perfectly steady, straight-tone singing. The tremor / instability Dr. Kim notes in my voice are consistent with what I've noticed myself in recent years especially.
Thoughts?