People who don’t realize they’re trans until adulthood aren’t really the target for people making rules for high school sports. Even college - if you’re a competitive men’s athlete, only to realize in your junior year that you’re trans - do you just give up on the men who’ve been your team mates and peers for years and try to form new relationships with the women’s team (if there even is a women’s team in your sport)?
We’re whittling down what was already a small minority of trans athletes to essentially unique hypothetical individuals. I don’t really think it’s possible to make rational rules to address every possible set of circumstances with such a poorly understood phenomenon. Best you can do is offer some guidelines, and minimizing distortions due to sexual dimorphism is a decent guideline. If there’s a male not beyond the size of competitive females, then that trans-woman seems fair to play with cis-women. If she’s the size of Jason Momoa because she’s been playing football as a man for 20 years, I doubt that a course of HRT will make her any less overpowering to competitive cis-women.
Maybe it’s just a sacrifice she will have to make, to postpone her medical transition and keep playing football, or begin her transition and accept that it will cost her the starting position on the men’s team without access to an equivalent women’s team. I mean, few of us can have everything we want, and most competitive athletes have to sacrifice some other aspects of their identity to be competitive.
It’s not just the people in power, though. When I look at primaries, where people actually have some hope of affecting outcomes, they consistently vote for the worst people. I mean, it’s hard for normal-ish people to even get to through the party structure to get on the ballot, and then they just get crushed. In 2020, Dems could have had Bernie, Warren, Buttigieg, even Klobuchar, but Biden won pretty handily. That’s on people people.