I have mixed feelings on the subject. If a trans woman transitions as an adult, she may have some physical characteristics that give her an advantage in some sports. On the other hand, if a trans girl transitions as a child and is given puberty blockers, she will grow taller until female hormones are started. That nearly always happens at a higher age than puberty occurs in cis girls, so trans girls may be not only taller on average than cis girls but taller than they would have been without puberty blockers. Trans women might therefore have sporting advantages whether or not they went through male puberty.
Perhaps the day will come when trans girls are given female hormones at the same age that average cis girls go through puberty. That would make the playing fields more even. In any case, trans girls probably don't want to be taller than most women.
Incidentally, I think that research should be done to find out whether children given puberty blockers become more intelligent than their peers, on average. Blocking puberty might also cause the brain to continue growing. The results could have great significance for future societies. In the Ottoman and Chinese empires, eunuchs were distinguished not only for their tallness but for their administrative acumen. In Turkey, the Chief Black Eunuch was almost as powerful as the Sultan and in China, eunuchs even became generals and admirals.
