> Even the Cass Review argues that blockers are entirely safe for AMAB trans people. It also argues that AMAB trans people have such a small percentage of detransitioners that it's basically disregardable.

I've read the Interim Report, it asserts neither of these points.

the Cass Review explicitly says "The rationale for use of puberty blockers at Tanner Stage 2 of development was based on data that demonstrated that children, particularly birth-registered boys who had early gender incongruence, were unlikely to desist once they reached early puberty" and only recommends reviewing puberty blockers for AFAB people.

Your quote misses out the part of the sentence immediately following:

"this rationale does not necessarily apply to later-presenting young people, including the predominant referral group of birth-registered girls"

The group referred to here is defined by being later-presenting. Female is only a subset of this.

Also, Cass is just describing the rationale, not endorsing it. This is implied by the paragraph immediately following, where she discusses the paucity of data regarding potential negative effects of puberty blockers on brain maturation:

"A further concern is that adolescent sex hormone surges may trigger the opening of a critical period for experience-dependent rewiring of neural circuits underlying executive function (i.e. maturation of the part of the brain concerned with planning, decision making and judgement). If this is the case, brain maturation may be temporarily or permanently disrupted by puberty blockers, which could have significant impact on the ability to make complex risk-laden decisions, as well as possible longer-term neuropsychological consequences. To date, there has been very limited research on the short-, medium- or longer-term impact of puberty-blockers on neurocognitive development."

> and only recommends reviewing puberty blockers for AFAB people

Cass does not make this recommendation.