One thing I would like to see and that urgently needs done is (in Rowantrees words):
"clarify and make explicit the difference between sex and gender and recognise the widespread confusion /potential risks / issues / obfuscation and / or misunderstandings which currently exist."
It needs to be explicit about the confusion and issues and address this clearly in legislation and/or practice.
The original GRA was designed as a legal fiction for a tiny number of gender dysphoric transexuals. We now have mass confusion about girl brain vs boy, magical thinking and biological denialism.
The purpose and meaning of enabling anyone to be legally recognised as the opposite sex needs to be crystal clear.
What else?