OR...and hear me out...there might be a new draft rule: Instead of being immediately disqualified for military service, trans folx are first investigated.
Their teachers, friends, relatives and co-workers are interviewed. Their medical history is reviewed. They are required to complete an evaluation with an Army psychologist.
Anyone found to be "faking" is charged with draft evasion (which currently carries a maximum penalty of 5 years/$250,000).
Anyone NOT found to be faking, e.g. all the "real" trans women, are now in a database. When the next piece of anti-trans legislation hits, or the next data breach happens, they will be that much more vulnerable.