I said "presents with female sex characteristics and" for a reason.
This only applies to this specific group of trans women.
If we agree on the effects of estrogen, then I don't think data is needed. This is a situation where I can simply use common sense (unless you disagree, then sure, I'd have to provide data)
Why would someone who identifies as a woman, but obviously looks like a man, as they didn't take estrogen, put on a wig and enter the male bathroom?
A big part of them would be the 60% who avoid bathrooms in the first place.
Most trans women who present with female sex characteristics are going to be on estrogen, because the alternative could in no way be pleasant.