The differences may well be material, but as I mentioned in the post above it's simply false to claim SA conflate the two when they link (multiple times) to an article looking at trans people specifically and also mention that they are healthy and safe when prescribed to other young people for other reasons. An article which links to an article discussing outcomes of a drug in young people that also mentions below that it's routinely and uncontroversially prescribed in old people would not be factually inaccurate, even though young people and old people are evidently not identical and it is not impossible the two have different outcomes.

The Cass Review itself offers no evidence the blockers are dangerous or inevitably irreversible (or if one takes a less cautious approach, cause patients more problems with irreversibility than not using them), merely finding that only two papers providing evidence for the treatment being safe and optimal were of "high quality" with others being of "moderate" quality or "low" quality and calling for another trial. It did not find higher quality papers drawing opposing conclusions. People more knowledgeable and cynical than me have suggested that treatments for other, less politically-charged but complex conditions may also suffer from the literature that supports clinicians preferred approach being of "moderate" quality but seldom face shutdown as a result. The side that trumpeted this conclusion (because it very much is political, even in the UK) delightedly concluded that as the favourably-disposed evidence mostly fell short of excellence, all gender affirming care must be shut down permanently. Perhaps you view things differently and would very much like to see the new clinics opened and a clinical trial designed to Ms Cass' liking devised, but it's safe to say most of the people trumpeting it as the last word in the debate would not.