@Tfmonkey
Ah, yes "The Tranny of Theseus".
My default position is that it is based on function.
If the trans-transplantee fills enough of categories they might as well be a woman. But before that time we are going to meet some weird mismatched traits and whacky half and halfs.
Before we can inject people with the Y-chromosome and upload "act like a man" brain trainers the treatments will fail to reach the goal.
Basically if you take a ship and start replacing a ship parts with plain parts...
@Tfmonkey
-you will have weird boat/plane hybrids.