before carrying out such interventions, any plastic surgeon will require a certificate or opinion from a psychiatrist, because the processes of transgender transitions are complex both in medical and ethical and moral aspects
To begin with, it is not clear why the question of biggender people, because carrying out some kind of operations and gender identities are completely different things. As for vaginoplasty, it is done by turning the tissues left over from the penis inside out. However, it is possible that it can somehow be made differently, but it is not clear from what tissues, and the question of the sensitivity of the neovagina will be a big question. I don't know anything about phalloplasty.