If someone has legally changed sex in Scotland, and the Haldane ruling in Scotland says 'sex' is not limited to biological sex, on what grounds would someone of their new legal sex be able to be excluded from single sex spaces and services? It's likely that service providers would be pressurised to be inclusive either through confusion around the law and what exemptions they can apply or fear of being sued.
Of course Scotland has already introduced self-ID under the radar in some sectors by letting a trans activist group pretty much write the Scottish prisons policy and withholding government funding from women's refuges and rape crisis centres if they don't accept transwomen.
What is 'going full female in dresses'? What is 'living as a woman'? Can you give me some examples of what 'living as a woman' means, that doesn't involve stereotypes of dress and behaviours?
Self ID as in wearing 'women's clothes' (they're just clothes, anyone can wear them) and choosing a 'woman's name' (they're just names, anybody can have any name) is very different from self ID enshrined in law which impinges on others.
I don't object to making it easier to get a GRC, with some caveats like over 18's. It's important to some people to have a driving license or death certificate with the sex they identify as on it and that doesn't really affect anyone much. I certainly don't object to people who dress in a non conforming way; pressure to conform to stereotypes is part of why we are in this mess. I object to gender identity completely over-riding sex in law.