I’m pre-op (but I just got my surgery approval from my insurance company today).
I’m not sure that GCS helps much in terms of “passing” (I don’t really believe in passing). Unless you’ve got so much that tucking is impossible…or you are changing in the women’s locker room or something.
What it could make is a huge difference in confidence, and that could make a big change in how you are perceived.
In my view, having surgery should be something that you feel a need for, at least at some level. It’s not that you have to hate your current genitals, but you should feel that a change in your anatomy will make _you_ feel better. Don’t do it for what you think someone else will feel about you.