@Crouton19
Males as a class have male advantage. The fact that a specific male or group of males has a reduced advantage doesn't matter.
CAIS males are over-represented in the women's category of elite sport. Since they will have come up through female sporting pathways and, with the same prejudices and restricted access to resources, this fact of over-representation alone creates a strong presumption of advantage. It's the perfect experiment. Males who look like females, are treated as female, still do better at sport than females. How can it not be a specifically male advantage/female disadvantage?
CAIS males are taller on average than women. As a class, they are taller. Height is an advantage in most sports and the reason they are taller is because they are male.
No CAIS male has periods.
If a woman does not have periods, something is wrong. Perhaps she is over-training, or has taken hormonal medication. A CAIS male without periods is a normal healthy individual.
You are making exactly the same argument as could be made for inclusion of a male with another kind of disability. If CAIS males are in female sport, why shouldn't disabled males or males with a performance-limiting medical condition also compete in female sport?
Which brings me to the fact that there is no reciprocity. Where are the females with DSDs doing well in men's elite sport?