Earlier quoted context omitted.
It's worth taking a step back to consider why we have separate categories for male and female sporting competitions, which is: the significant physical advantage that male development confers on an individual. If sports were mixed-sex, males would dominate almost every competition. So we have women's and girls' sports separate from males, to recognize and celebrate female athletic excellence. With that in mind, it sh…
This argument devolves to "we can't let women compete until we dissect them". At what point in a woman's competitive career do we decide that she's sufficiently talented that we have to examine her body and approve of her gender expression? Is it reserved for Olympic athletes? Or do talented college women need approval? Skilled high school students? A surprisingly good tee ball player? Down this path lies madness. Yo…
Only if there is an anomaly might further investigation be done, with the athlete's permission. No dissection is needed - at most some imaging to determine internal anatomy may be done by medical experts.
This is already the policy adopted by some sporting bodies, and was essentially the process used with the athletes I mentioned in my earlier comments to observe that the sex of each is male.
Ideally this would be done as early on in an athlete's career as is practical. It only needs to be done once, as a person's sex cannot change, and for most will be a straightforward confirmation of what is already known. Otherwise, it's better for the athlete too, to know sooner rather than later if there has been any anomalous development.
I would suggest you examine the public information on the aforementioned male athletes more closely. In particular, 5-ARD is an indisputably male condition; the mutations in the SRD5A2 gene that cause this have no effect on female sexual development. This is fact, not opinion.