You are right wingwalker.
With regards to how its actually treated by doctors and mental health professionals Berleigh, the DSM is by in large ignored and its treated as a "gender and sex issue". Very few doctors or mental health professionals like the DSM at this point.
Basically speaking the UK is very much behind the US in some regards. The biggest one is the fact that nobody can block treatment and they do not consider it a mental illness anymore, even though the diagnosis in the DSM suggests it is. Its a confusing state.
Basically it is very rare somebody will be blocked from HRT or Surgery if they jump through the hoops, and it is honestly not very arbitrary. Also taking the LGBT clinic system has taken on HRT and therapy in many large cities for TS, everything has become very patient directed, less about thinking your mentally ill, etc.
Pretty much as it stands the US is a bit more trans friendly in the treatment approach. No forced RLE for HRT (which is common in the UK), no clinical treatment as one is insane, and generally its patient directed. Basically you do things when YOU want to, not when the doctor wants to. Even the SoC are begining to be seen as more of a guideline than anything.
Basically Berliegh psychiatrists no longer play on this as you are suggesting, in the US it is very close to what you are suggesting its like in Scotland, at least in practice.