I invite you to explore your own consideration. You say there's separation for a reason, but what's the reason? Is it practical or ideological? For instance, clothing regulations and criticisms are heavily ideological and adhere to traditions more than they do to the needs of the practice or individual choice. So, is the separation issues being brought a result of experience and reality? Do we really need a new category to put individuals in because a few from a very small group excel? Michal Phelps is an outlier, but the sport didn't change because of his advantages, because it doesn't make sense to.
What I'm trying to say here is that there's no real problem being discussed when we talk about trans people in sports, just a hypothetical one.