My hope is that once the NCAA has had a couple of years to see the positive response to doing something >75% of Americans support, and to see a few of these altered-birth-certificate cases crop up, they will move to a cheek swab.

Back when I knew nothing of the Trans demands and was a neutral/supporters of the "trans people", i was really put off by the fact that we were changing birth certificates. I couldnt wrap my head around why that was acceptable. Even if you believe people can change sex it doesn't make sense. People can definitely change weight and i don't update my birth certificate regularly to reflect my current weight. So why would we allow them to update a historical document to reflect false information?

I think you hit the nail on the head though. "Hello fellow womens! I am a 'cis woman' just see my birth certificate showing i have been female since birth! But please be kind, I'm on my period you see and that makes me cry constantly while talking about lipstick."

I'm not sure what rule the NCAA could have crafted that would completely avoid confusion and controversy if/when a TIM whose birth certificate was falsified when he was a child competes in women's sports.

I thought the NCAA rules allowed for further investigation if questions remained.

Yes, they do.

Worst case, a well-passing juvenile TIM holds back his natural advantage in a meaningful way (vs. Lia Thomas and others who only did so when they started getting scrutiny, and, even then, not by much) so no one goes looking for his actual sex. And I'll take that over TIMs arrogantly crushing the female competition, obviously gloating about it, and then playing the victim when people inevitably, and justifiably, get upset.

Yes, the NCAA has created a huge loophole by saying in its new policy that women's NCAA competition is closed to athletes "assigned male at birth" rather than saying women's NCAA sports are closed to male athletes.

There's also a big problem with how the NCAA policy defines "sex assigned at birth" to start with:

Sex Assigned at Birth: The male or female designation doctors assign to infants at birth, which is marked on their birth records.

This phrasing ignores the fact that most people born outside the USA did/do not have their sex "assigned" or recorded by doctors at birth because even in countries with modern medical care and medically-monitored births, most of the world's women give birth without a doctor present.

Moreover, most people in the world don't see doctors as infants or during childhood unless they are/were seriously sick. If/when people outside the USA see and are given physical checkups by HCPs at birth, during infancy or later on in childhood, the HCPs are almost always midwives, nurses, nursing assistants, home health visitors, school health officers, dental technicians - not medical doctors.

The whole new policy is a shitshow.