Bev made some great points about gay and lesbian rights and the importance of biological sex, but I thought Benjamin ultimately presented the stronger case on 'self ID'.
He did very well bringing everything back to the mental anguish of people who wish to be legally recognised as the opposite sex.
This framing is what has won the trans movement the right to falsify legal sex in the first place - long before 'self ID' was ever on the table. The argument goes: we desperately want to be the other sex, so much so that we will kill ourselves if society won't play along with this, and doctors agree this is a real thing.
It takes some chutzpah to argue that trans is not a mental illness, while at the same time using mental illness as the reason why trans demands must be met immediately and without question, but it has been a very successful strategy so far and will probably work to win 'self-ID' too.
It reaches people's most basic sympathies: most people think that it must be awful to feel like you were 'born in the wrong body', and thus when trans activists say 'these are the legal and social measures we need to alleviate that suffering', it seems reasonable to many people, especially when they haven't thought about the detail of how this will work in practice.
The problem for the 'gender critical' position is that the 'trans rights' framing means that they are essentially reduced to arguing for more red tape around a legal fiction that, we are told, is necessary because it is a medical emergency (suicide risk).
Benjamin: let people be legally recognised as a sex which they are not immediately, it's cruel to make them wait two years when they are in an emergency mental health situation.
Bev: it's important that people be legally recognised as a sex which they are not, but have a doctor sign off on it and make them wait two years first.
Nowhere in these arguments does anyone get to the nub of the issue, which is that no one should have the 'right' to be legally recognised as a sex which they are not. It is not a 'right', but an unreasonable demand. This demand is contra to reality, infringes on the rights of women in particular, and is ultimately socially unworkable on a large scale.
This is the case that needs to be made, strongly and unapologetically. If feminists keep framing it as 'trans rights vs women's rights', 'trans rights' will win every time, because trans-identified people are perceived to be the more vulnerable group, owing to their mental anguish and purported suicide risk.