In some situations, for the safety and comfort of all concerned, the plumbing must trump the preferred identity! Nobody with a penis has any business in a ladies' loo, changing room or women's prison and nobody with a vagina is safe in men-only spaces.

Once full surgical transition is undergone, then the problem no longer exists and one can and should use the facilities approrpriate to ones' identity.

In the matter of sports I would humbly offer the opinion that there are about a million more important things to worry about!