@FifteenToes just to respond to part of that
I don't want to dwell on this as it wasn't my main point (although if I did, I might point out that if there were any that passed so well you didn't notice, then you wouldn't know, because you didn't notice).
I also don't want it to be glossed over. You say you aren't a woman so you won't know how it feels to be a woman in any single sex space when a transwoman enters: Many times women paused, felt a moment of fear, anxiety, discomfort and then stopped and, quite contrary to their own feelings, chose, as in an active, self checking, double think, to not notice the man in the room. Many times I have chosen to 'be nice' to try and equate the male bodied person in the room with me with spiders - you know "more afraid of you than you are of them". I have even felt ashamed of myself for feeling nervous: bad woman, poor transwoman. Because we do notice, have always noticed. You cannot change the way you move, the sex based differences in gait exist and cannot be erased (I'm an exercise physiologist by education, trust me on that one).
How do mean feel when they see a transwoman or transman in male single sex spaces? Is it fear? I doubt it.
Transeople who have so much intervention, surgery, coaching etc that they do tend to pass? I know 2, a transman who passes quite well, until he laughs, or walks. A transwoman who passes quite well, until she moves, or laughs. I have known them both for 30+ years, supported one through many surgeries and was the 'best person' at the wedding of the other. I know how hard it is for them to manage their personal expectations with societal mores. Neither of them think they have changed sex, both of them have had all the surgery possible and have a GRC. The transman uses male facilities. The transwoman uses single cubicles and checks her day to make sure she can!
Why the difference? The transwoman is fully aware that she makes women nervous. The transman has never had anything more than a sideways look - and uses cubicles. Yes! That same sideways look transwomen get, because men see it too! The gait, the whole body language is a giveaway. You see it, especially in motion.
Personally I don't know how to square that away. When people modify their bodies iin extreme manners, like the lizard man upthread, their choices make them 'other'. They should have, prior to any body modification have thought all of that through - you know, the much makigned talking therapies, watching, waiting and thinking before launching on any medical intervention.
There are times when the answer is obvious - transmen in female facilities like prisons for example. Or no transwomen or transmen in female sport beacuse of either natural or chemically enhanced performance. Transmen in some but not all sports maybe, if they are not in physical danger or have an advantage. See how complicated it gets?
And that is why this rumbles on. There is no simple answer, no matter what your perspective is.
But that doesn't mean women need aquiesce to the demands being made around the language, rights and safeties based on their sex.