I’d like to interject that it’s not necessarily the evidence that mixed, but its interpretation. The same data can be taken two different ways.
I just finished reading a link (wish I kept the url) that argued trans woman runners still outperform cis women by 12% after 2 years of hormones, pointing out the competitive requirements are only 1 year of hormones. Only in the subtleties do you find that their metrics for performance did not just involve running speed (but included push-ups), and that the underlying research admitted in conclusions that they were likely over-rating the trans women’s competitiveness…
One of the things that I read somewhere that REALLY stuck with me is this. There will always be an "evidence-based "argument to attack trans atheletes so long as there is at least one trans athelete that is outperforming cis atheletes. If trans women are equivalent to cis women, then the real answer is that it should be even (weighted obviously) odds that the best in the world would be trans or cis… but what we seek to validate “fairness” is that no trans athelete ever actually rises to the top. Because if they do, it must have been their gender advantage.