It seems to me that FoodUnit you don't believe that transpeople exist, and refuse to look at any evidence that they do.
You seem determined to maintain the male/female divide as somehow sacred, whilst also simplifying it down to anatomy, something easily altered.
Consider why the male/female dichotomy is so important to you? You seem reluctant to recognise the idea of a 'typical' man or woman, yet insist that the two are totally different.
If feminism's aim is for society to recognise that men and women are different, and to ensure that things are set up to cater for both sexes' needs, then how do transpeople threaten this?
The only explanation I can find is that you assume that trans are intentionally trying to erode women's rights, which I cannot find any evidence of at all. I see no reason at all to exclude mtf trans from any women-only space, it's not something you can have grey areas for IMO. To transition sex is legal, to insult a transperson is hate speech, so how can you decide that you will ignore all of this? It is so, so few people and itis heartbreaking to think that you will not allow them to be fully recognised as women despite their being legally so, when your reasons include that they might sexually assault another woman. How insulting. You have no evidence to show that it is even a remote possibility.