they often do not behave as allies insisting that their experiences of sexism mean that they can’t be racist
Have you ever heard anyone saying this?
I'm asking as someone who has witnessed racism countless times and witnessed white people denying racism countless times when they have been or are being racist.
I have never, ever heard a white woman saying that she cannot be racism because of her experience of sexism. I'm not saying that it has never happened, but I have never experienced this and cannot imagine that if a woman said this that it would not be called out quick time by other women.
I have witnessed white people, including women, jump through various hoops to try to deny their racism. One of the most ridiculous being "race doesn't exist - it is just a social construct, therefore I cannot be racist".
That one has to be up there alongside, "but I really find black women / men attractive / I have had relationships with black men / women", "some of my best friends..."
I am pushed for time today but one way that I may be able to be an ally to you and to BME women is that I have for some years worked extremely hard to research the astroturfing of activist movements by sinister actors.
I can show you some of the ways in which BME women's (and men's) struggles have been appropriated and astroturfed by cults, criminals and other sinister forces if this would be helpful and I would be pleased to do this free of charge as a way of showing my commitment to the struggle.
It may take me a day or 2 to put a few things together and even then it would just be the start as I have a lot of data to share.