Dr. Haben in Rochester NY does a very similar procedure and by now has significantly more iterations than Yeson did when Dr. Kim was starting to become popular back around 2011-2013. The post-op voice quality is similar, and as with Yeson, the overwhelming majority of ladies who he works on report a good-to-excellent outcome.
Ps. I share your apprehensions about all the recent insanity regarding NK; but even aside from that, going forward we will need more than just a couple reputable voice feminization surgeons, so it's good that there is someone taking up this mantle in North America.