As a cis woman, I have never felt unsafe with my trans woman friends. But I have felt unsafe as someone who doesn't perfectly fit into the expectations for women around people who are obsessed with policing gender and catching out all who don't fit in. I have a strong jaw, thick brows, broader shoulders. I'm terrified of the idea of being asked to "prove" that I'm not trans and what that entails. We've seen people in other states be harassed to prove it by exposing body parts they have NO desire to because of this fear that they might be a trans woman. And yet trans women are seen as the unsafe ones over the people who want to enforce this. 

The harassment trans women would receive in male spaces for existing as themselves also puts them significantly at risk, and would likely lead to them avoiding these facilities or group sports altogether. It would be a shame to push people out of community and activity in it because of a few loud voices. I don't want to have to live with scrutiny in public changing rooms and locker rooms because of this or have my trans friends pushed out of spaces they belong.