I think this question concedes that there is some possibility that one could experience an incorrect puberty.

Given the definition of maturity is being fully grown, this comes across as an inherently unhelpful thing to ask. If we say “only once someone is fully grown they are able to determine if they experienced the incorrect puberty” then this makes it impossible to help children who are going to experience the incorrect puberty. Unless we have some way to determine a child is trans without any input from them, there becomes no way to help them.

The possibility of being unable to help people is not an excuse for hurting them or others. Generally if you can't know the correct action than you should stick to the status quo.

What's next, gene therapy because the embryo might want to be a different race when it grows up?