I don't think professional cis women athletes who are against competing with transgender women make up 50% of the population., so I don't understand what this generalization is supposed to achieve. 99.9% of women will never be affected by any of this.I appreciate how you got to this position and I think you're concerned with fairness and being an ally to a marginalised community.
I have to ask, why does 50% of the population have to be ignored and forced to cater to the wishes of a tiny minority that come exclusively from the other 50% of the population?
Secondly, if a trans athlete wishes to play sports, why can they not play in the group they used to play with?
Genuine questions.
That small minority of women must be listened to and there are legitimate concerns. You'll find examples of transgender women agreeing with it. My position is that until there is an alternative that makes everyone at least a little bit happy, then exclusion is not an option. That's it.
You will have to ask transgender women that second question, although I make the distinction between playing sports and playing professional sports.