I would add also, for a pre-op transwoman or one who has had their testes removed but still has a penis, other users of a public restroom are not going to look under the cubicle door to see which way their feet are pointing.

And let's not also forget that estrogen therapy means that a pre-op transwoman cannot easily have a spontaneous or morning erection. TERFs love to trot out examples of rape by transwomen, but such instances are rare. And let's not forget this, are people calling for all men to have their testicles removed because some are rapists? No. So, how is it rational to say that transwomen should not be permitted to use women's toilets on the flimsiest pretext that a minority might be rapists?