I am concious about the unpleasant attitudes of some people about trans people using changing rooms
Aargh, the bullshit!
No, it's not about "unpleasant" attitudes about "trans people".
It's about perfectly normal, reasonable, statistically backed-up, and widely understood and legally accommodated, fear, discomfort, loss of dignity and and feeling intimidated, by FEMALE people about MALE people in a woman's space. It is because males can be very dangerous to women and there's a pretty high prevalence of harassment, intimidation, flashing etc., and being seen undressed by the opposite sex against your will is not something our society normally expects people to tolerate, that women's spaces exist.
No one is saying trans people aren't allowed to get changed. It is about what sex you are. SP isn't freaking out about trans people, she has made very clear it is the maleness of BU that was the issue (and being given a hard time for that!).
The misdirection and gaslighting is off the scale.