Transitioning female to male doesn't make you more likely to win Olympic weightlifting competitions in your new gender, so you'd be vanishingly unlikely to do it for the sake of gaining an advantage.

Ah. We are only considering physical advantages then. There can be many other advantages that are not physical.

Keep in mind that transgender individuals are almost certainly, in general, and by regulation if they are transgender and an athlete, undergoing hormone therapies. In the case of estrogen treatment, that implies a reduction in muscle strength in addition to the other physical changes caused by the addition of estrogen and the removal of testosterone.

This is a factor in why there are regulations requiring testosterone levels below a certain amount in order to qualify in the women’s section of certain sporting programs.

There are no zero sum advantages to being a man that can be harmed by a FtM entering the pool.