If you naively consider the topic only from a bodily autonomy perspective, then the answer is deceptively simple: get the blades out and start slicing. But this ignores the wider medical ethics concerns over whether it's the right thing to do for the patient, if the surgeon is causing harm by doing so, if gratifying the patient's short-term desires genuinely helps them in the long-term over their entire life, if it's reasonable to expect a surgeon to perform such a procedure and how they may feel in the aftermath, if there are any other interventions that would be more effective. And societal questions over whether it's ethical to deliberately add new members to a population who already find it difficult to find the support they need, how this will affect others who may now be situational obliged to assist with this person's new disability, and so on.
It makes no sense to focus solely on the individual and ignore the wider context, when there are so many other factors to consider.
So this strawman won't stand.
So before you go off on a tangent about what is and is not accepted practice and which things doctors are required to do and which things they abstain from on ethical grounds I will have to bow out because we are at the limits of my knowledge on the subject and that's not for want of reading material. Let me close with: I know where the line lies in simple cases, but if you start dragging in things that I have not spent enough time on/read about/have knowledge about then I simply will not be able to hold that conversation. If you have this knowledge then more power to you, but so far you have not convinced me of it and you come across as an ideologue.
Pot, kettle, black.
The social context has nothing to do with it, that's just a way to say that if enough people say that you can't do to yourself what you want to that that makes them right, which has historically led to all kinds of wrongs. See also: the right to euthanasia, abortion, being gay and so on and so on. It's always the sanctimonious groups that are hell bent on telling others how to live, but it never was any of their business.
How 'we as society' view this has no bearing on something that is ultimately the domain of a single individual, the person affected.
In the United States this is codified by "The right of the people to be secure in their persons" though of course there is plenty of hairsplitting going on about what that actually means, even though the simplest reading is to take it for what it says.
The implications of this are far reaching (for instance: I'm on the one side against a vaccine mandate because it would infringe on that right, on the other I think that a lot of people have allowed themselves to be pushed towards this on a pretext).