"Matt is coming with us. He said he'd be at four. Jemima is also coming they said they'd be here at five."

Matt is coming at five? No Jemima is coming at five. Matt is coming at four. Also Sarah is coming with her partner Zoe. Ze said ze would be here at 4 also zey're getting a ride with Matt.

Umm. Ok.

Not to mention that now when I talk about women, I have to also consider every other gender non binary person as requested by OP. He doesn't want it to be essentialized and pragmatically to be inclusive one has to therefore moderate all language relating to gender.

That is a significant cognitive load and I wish people would stop pretending it's simple. I live around and have friends who are trans/binary non gender people and it's hard work keeping up.