Yu-Ting doesn’t even have the excuse of having been born in a rural region of a (by Taiwan’s standards) poor country like IK.
I’d be very… surprised… if he’d not had a DNA test / scans when his puberty wasn’t a female-standard one.
He seems to have dodged a lot of the scrutiny that IK’s been subjected to, at least in the UK press, so I’m not sure the embassy’s done him any favours by making this request.