The true believers don't change their minds even once they do understand the implications though.
I have spent many an hour debating Schedule 3 issues with TW friend, to no avail, because 'it's more complicated than that'.
So I switched the question. If I could prove harm (injury and unfairness to sportswomen, crime or fear of crime in prisons or changing rooms, exclusion of religious women from public life), would TWF accept Schedule 3 restrictions (or, in the alternative, 'trans-inclusive' and single-sex services existing side-by-side)?
The answer is no. TWAW, it's just the way it is, and the necessary consequence is that they must have identical rights to women, even if there are unfortunate downsides. And the religious women are just bigots, so don't need accommodating.
In some ways, this seems more intellectually coherent because it doesn't rely on denying the attendant harms. But, of course, it ignores that Schedule 3 is needed because of the physiology underlying those harms (when I mention this, the argument goes right back to 'it's more complicated than that'). And it ignores the fuzzy boundary between TW and other men (answer: 'there's lots of science! Anyway, we are tiny in number and so vulnerable')
TL:DR It's a quasi-religious belief shared by fewer than 20% of us, so no point trying to argue them out of it.
We've never progressed to debating S158-159 or Schedules 9, 12, or 16, and at this rate we never will.