That's why transphobes shouldn't set the rules. And when the rules are set, there will be backlash, which needs to be ignored by the scientific community and the authorities governing professional sport.

This is a tall order, but I do think the question of where the line must be drawn to guarantee fairness is a question worth answering, preferrably not by me, because I don't have the credentials to deliberate on what's fair and what isn't. This is the role of science.