How about non-unisex toilets and women-only domestic violence shelters? Personally, I oppose them, but it appears that most people support them, "discrimination" not-withstanding...

"women-only domestic violence shelters" what exactly do you oppose? That there are no equivalent men's shelters, or that men aren't allowed in?

To this day my wife refuses to tell any man the location of her shelter from when her ex abused her. Might not fit into the modern gender zeitgeist, but I fully support her.

Domestic violence agencies could certainly abuse male victims less. A study of male domestic violence victims who contacted local domestic violence agencies for help found that 40.2% were accused of being the batterer by the person "helping" them:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3175099/#S12tit...

Unequal availability of assistance/capacity.

OP said: "women-only domestic violence shelters"

Having men-only domestic violence shelter hardly requires removing the gender requirements of our current shelters.

Define "discrimination"

Is is discrimination to require a fitness test be taken for certain jobs/insurance?

Discriminating based on fitness instead of gender is exactly the sort of thing one should do, if fitness is really what you are worried about.

That way, the occasional woman who is if fit enough can still do the thing that needs doing, and flipping genders on your birth cert doesn't game the system.