That's revolting!
Transmen are legally excluded from women's spaces anyway if they are male-looking enough, so that's the end of it.
If a transman is stood there facing you with a pumped up bit of surgically attached forearm sticking out of their vulva (unlikely) that is sexual assault and you can get them arrested and removed from the premises.
Why would your thinking even go there? !
That is such a typically male thought trajectory
-It's why we don't like you in our spaces!