I think that most women if they are in doubt, will not say anything. So masculine looking women and very passing transwomen will be left alone. Women might hurry out but it takes a lot to challenge someone in the womens toilets. And unlike what most transactivists think, most women aren’t mean or out to hurt people.
Changing rooms are different, less place to hide. Then it is also clear if the person is a masculine woman or a feminine man, so I would expect most of the challenges there.
in sports, it is often known within the teams so hard to keep quiet if there is a transwoman playing. Plus at a certain level sports are asking for medicial verification.
Healthcare, medical records should never ever be changed. It is dangerous to change the sex identifier and I would expect any drug usage is clearly added.
I am sure practical solutions can be found. But transactivists don’t want practical, their starting point is that transwomen will break the law and harrass women in womens facilities and endanger them in womens sports. Their opinion is that transwomen are incapable of following policies and laws like other people can. I think transwomen are better than that but lets see