> Do trans-athletes regularly out perform "born as" (not sure the best way to phrase it) athletes?

No, both because there are very few trans athletes in competition, and because trans athletes (except trans women who have not started or are less than a year into hormone therapy) have net athletic disadvantages, when considering all factors relevant to performance in almost any real sport, compared to cisgender people of the same gender identity.

I mean, if you had a sport that isolated grip strength alone, trans women would have an advantage over cis women, but aside from rather contrived cases like that, they don't.

There's a reason the poster woman for the political movement around this in the US is a cisgender woman whose story of "unfair competition" is tying with a trans woman for fifth place behind four other cisgender women (and having to hold a sixth place trophy in photos, since there were not duplicates on hand for the same rank) in an intercollegiate swimming competition.