In the face of that, continuing to claim that fear is reasonable

I didn't say the fear was reasonable. In my last post, I said the fear may be unjustified (although I'm not as impressed by the data as you are). I'm just saying that that you described a different fear - a fear of potential illegal conduct by trans women - in your OP. I believe the OP wording implies that cis women are transphobic rather than (rightly, if in this particular case unnecessarily) male-phobic.

You may be right that some transphobes make the "false flag" argument disingenuously or accept it uncritically, and that it contributes to transphobia - although, again, that seems easier to say than establish - but none of that rescues the verbiage in your OP.