As a sticking plaster it's better than nothing.
But fundamentally it's still a step backwards for women (female people) because it still validates the sexist and frankly batshit beliefs underlying the demand to choose your toilet (and other single sex provisions) based on your subjective and variable personal identify not your factual and unchangeable sex.
Those underlying beliefs being:
a) men and women are types of mind
b) the physical need of the fenale body have nothing to do with the existence of woman-only spaces, protections, supports and opportunities
c) how society treats people with female bodies has nothing to with the existence of women-only spaces, protections, supports and opportunities
d) women-only spaces, protections, supports and opportunties exist because of the needs of people with a women type of mind
e) a male person can be a women if he has the right type of mind
So, #BeKind or not, I'm uncomfortable supporting any solution that accepts the sexist belief that some men are different to other men because their minds are closer to a mythical womenmind.
Note, that doesn't mean I'm anti third spaces, or any number of spaces. If society wants to restructure itself based on personality type and trust people to correctly self-identify as "sort, harmless, a bit overemotional" or "mathmatical and lacking empathy" or even "uncomfortable with shades of yellow, prone to practical jokes, likes hats" that's something society could explore. Maybe there's a good case for it, maybe it will bring all sorts of benefits.
What I am anti is any attempt to redefine the facts of sex into a system based on sexist stereotypes.