I'm Australian so I can't really comment, which of course has never stopped me.
There are a number of police woman on the site who have transitioned. I'm not sure if that means they are Fed or not, and there are several ex service woman who are on site. Not sure how they fit in to your question.
There are also a number of problems at the moment with access to the site so be patient in waiting for answers. I think the USA Vets were saying they did get some support.
One I do remember was the Head of Dade County Police who transitioned 'on the job' you can probably find her details easier than I can.
One thing that is worth mentioning is to talk to your human resource people quite early in the act. They know the laws and have to enforce them. It is easier to get them on side early rather than late.
Again from an Aussie perspective (upside down

) they organise my toilet arrangements and my care arrangements and counsel people who may have problems with what I'm going through. With a bit of seniority, tact, tears and knowing the law, you can make your problems theirs. Which I'm very happy to do. It doesn't mean you will not be discriminated against, it means you can sue the ass off the employer, and HR have to support you because they had prior knowledge and therefore had to understand the legal implications. Even if they didn't.
In practice I have had no problems. It may be different in the USA military machine, but from what I understand you are now mainly an office based person rather than a field combatant. My intelligence and ability are not affected by my gender or how I'm dressed. I do follow the proper clothes code for my profession. I seriously doubt that your gender affects your job, it hasn't so far and your gender has never changed. Your sexual identity is also of little importance in most jobs, and your sexual presentation only really becomes an issue if you want to work in a profession were overt sexual presentation is important.
I believe you have a chain of bars? called Hooters? where the waitresses were skimpy clothes and look overtly bimbo female. You may not qualify for such a position. But i sort of doubt that you want that sort of career.
In an office based career I think you may well find females and males contributing equally.
What is between your legs has little impact on your ability to do a good job. IMO.
I even know some guys who can think

You just have to prompt them. But getting them to have an attention span to put down the toilet seat is impossible.

Cindy