Agreed. NICE is tightly regulated in what it can tackle and its methods and processes.
ChaCha - I doubt genital surgeries would turn out to have a reasonable cost/benefit ratio if any one in the NHS or NICE took the time to look into it.
I can't think of any NICE programme that would invite a sex realist organisation to be a stakeholder or recognise any such third-parties as relevant stakeholders.
Much would depend on the nominated clinical experts and who nominates them. Or which clinical/lived experience experts are recruited to any contributory Delphi processes.
Moving to other funding mechanisms, I'm fairly confident that if the argument is always, "But profound unhappiness or self-euthanasia are likely outcomes without this intervention" then adult gender identity services, specialised commissioning or individual funding initiative applications would accept the cost/benefit.
I do wonder where the estimates for post-surgery follow-up care would come from. Newgent's follow-up costs have been horrendous. But, I've no idea what (say) Watson's costs are.