Sometimes GG's in groups get called "guys" like "so whaqt can I get you guys?" It is not a rude thing, just a knee-jerk response even if there is no mistaking they are GG's. OR if it is a mix of men and women the group as a whole gets called "guys", just probably slangish. Nothing more.
For me, when I am out with my wife (seldom) we always seem to get called "ladies", even if I am making little effort to try to look femme. I know that contradicts others' experiences.
Yes there are tons of threads about "passing", but you kind of have to get to where you don't obsess about it. Sure I think about it a lot but really, if I get called "ma'am", it feels good but it doesn't make my day, or if I get called "sir" it bothers me a bit but doesn't ruin my day.
I think the only time to really worry about this "passing" is if you are trying to go stealth, like if that is even an option in the first place. For someone like me it might be possible, but would cost more in surgeries than I could ever afford.
The best thing to do is to present as tasteful as possible. I mean even if you are read, it isn't going to make a scene as much as if say, you try to go out dressed like Britney Spears (unless you really have the youth and figure to pull it off).
I know from experience that having to bust ass to be anywhere near passable does suck, it's hard and don't always work, but being born GM's and having a lot of disadvantages, we can't beat ourselves up. If we had great female bodies and somehow let it go to waste (like if a marathon runner gained 150 pounds by eating too much junk food) then we could feel guilty but do the best you can with what you have. What else CAN you do?
Just think, a lot of GG's out there wish THEY looked perfect too.