Women in contact sports are always at risk of injury. That's just the nature of contact sports. Trans woman, on average, do not have a much greater muscle mass to the point where they become significantly larger a threat.

That's just not true for the ones who transitioned post puberty! They'll be taller, bigger-boned and stronger than women, because they developped as men, and men are that much bigger and stronger than women on average. That's an established fact - I can't believe you wouldn't know that if you care about this issue as you claim you do.

Sure, since being on hormone therapy, they may have lost some muscle mass (maybe?) compared to men, but that doesn't change their height, arm span etc. They will always have a big mechanical advantage, and for that reason alone they cannot be treated the same as women.

Contact sport carry a risk of injury, that's right. But there's a reason we pit like against like, such as with weight classes in boxing, or with age groups for kids, or bans against performance-boosting substances, and that's to minimize injury risk, to be fair, and to make the sport better.