I think you need to keep the sport safe and fair for women while balancing the real benefits that otherly sexed women get from participating in sports. I'd lean towards younger other sexed competing so they can have those social interactions while letting women in the more common hormonal range compete.
So I'm thinking something like:
-high school, let anyone compete and win championships but no state records. Delicate minds given the opportunity to interact socially and gain confidence in a time when a fair number go through some very difficult times.
-college, all women can compete in non-contact and non-team sports but no championships and no records. No competing in team sports because the other women on her team won't be able to compete for championships. No contact sports for safety reasons.
-international competitions, no other sexed women can compete