FFS as far as I am aware the cohort that need inclusion in respect of train travel are people with a disability and possibly pregnant women and people with very young babes/children. DSD, Sex, race, religion, sexual orientation, marital status, gender reassignment etc. are not relevant when travelling by train. Toilets are unisex so no issue.
People with DSD have my sympathy, they are continually being dragged into a debate they want no part of.