From my understanding, he does specialize in turning girls into guys and guys into girls. Its ALOT easier to turn a guy into a girl, because guys generally have MORE in terms of face bones, which need to be shaved down. Shaving bone down is MUCH easier than building bone up.
He uses his trusty burr to file down the brow ridge and gabella bossing in men who want to look like women. This is relatively easy and effective at removing the male sexual dimorphism in the brow ridge.
The other way around is alot more complicated. The brow ridge of a man has more bulk AND projection than women. To add projection he uses the osteotomy, which is stabilized with a combo of bone graft and substitute, while bulk is added with bone cement, likely a HA paste. HA paste is amazing in places like the brow ridge, because it forms a tight scar capsul which prevents migration of the granules, and promotes osseointegration.