Outsideness

"Such eugenics would be practiced by elite groups, whose achievements would so quickly and radically outdistance the usual tempo of evolution that within ten generation the new groups will have advanced beyond our current form to the same degree that we transcend apes."

Well, it's not as much eugenics in the case of trans women as environmental selection. The dysphoric men most likely to transition are those with well-paying professions, "progressive" open surroundings and an unconventional, non-traditional outlook, who are on average smarter.

People who deviate from the norm in a way that makes them feel repulsed by "traditional" societies are more likely to embrace the "otherness" of being trans. So the environment selects for intelligence and creativity, but also for many mental illnesses (autism, depression).

Where this gets interesting and feedback-loopy is when we start engineering selection pressures on our own environment (or our interfaces to it). (hi, I'm cis, but autistic and sometimes psychotically depressed and experiencing a far better quality of living through chemistry)