I can see a case for this being made available on the NHS only if there is a reasonably reliable to way to tell the difference between someone who is genuinely transgender and someone who is suffering gender dysphoria, which people overwhelmingly grow out of naturally.
At the moment, there is no way to tell the difference, so even with all of the checks and conditions applied to these treatments I am uncomfortable with it being publicly funded.
I also think the trans lobby needs to figure out whether being transgender is an internal biological thing (in which case this treatment becomes a valid part of treating a medical problem), or whether it is a question of identity (in which case it is cosmetic). At the moment we hear messages going both ways to deliberately "mystify" the experience of being trans. A decision has to be made.