I have long hair (dreadlocks) and my clothing style has always been as it is. That coupled with my feminine voice and massive bum means that I'm certain I will never pass without the help of hormones lol. I'm OK with that, I guess, so I'm trying not to get hung up on passing, though if it ever happens, I'd be thrilled beyond words.
So I can't really comment in that sense, but the first time I wore men's clothes entirely, as well as tying my dreads back as per the suggestion of someone on the site who said guys tend to wear their dreads in a ponytail, and wearing a binder, I felt awesome. Didn't speak to anyone, and people here don't really use sir/ma'am anyway, so I wouldn't know what they thought. But I felt very comfortable and confident, which is amazing considering how bad my anxiety is.