I know a trans person. I knew them before their transition, when they were using their dead name. I know them after their transition, and I can see such a difference in them, how living their true life has given them such confidence and just changed everything for the better.
She has chosen her new name, which totally suits her new life. I havent seen her for a few years, we don't live in the same area but if we did meet up and go to lunch and had to use the toilets, then it would be just the same as with any other female I know. Girls go to the toilet together, thats just what we do.
The issue with trans people in general, I think, comes from the fact that not every trans person can pass or wants to pass. There are trans people on YouTube , on TV etc and you would never know they are trans, and if you saw them in using female toilets, there would be no issues.
Its only when a trans person who does not pass , for whatever reason, that it becomes an issue.
Since when did it become ok to have so much interest in other peoples genatalia?