All that is needed is the intention to live in your acquired gender for the rest of your life.
Yeah, Pippa Bunce. Woman some days, man some days, depends on how they feel when they get up in the morning. Plenty of cross dressers who enjoy the sexual experience of cross dressing (trans and fully entitled to all woman access according to Stonewall) limit it to weekends and holidays since it doesn't mix well with working life.
And no evidence to be requested: means in practice that under self ID any man walking into any women's facilities will be assumed to have self declared just by walking in. Self ID means, in fact, any bloke can walk anywhere into the most private of women's spaces, and expect to be accommodated there without question, regardless of what distress and embarrassment and negative impact he may cause to the women in that facility.
The banging on about 'declared intent' is asking women to trust that everyone will be jolly good chaps and never abuse this open door access.
So let's ditch background and police checks for people working with kids and vulnerable people, eh? They can just self declare they're nice people who never abuse anyone and nothing can possibly go wrong.