I think passing has a spectrum and it's all in the eye of the beholder.
Do you still get "sir"? How about "ma'am"? Or do you get gender neutral or not gendered at all?
On the now rare occasion I get misgendered, I get very introspective. Am I where I thought I was on the continuum? When my friends respond that the person was rude or ignorant, I take it as a cue I'm not where I want to be. My goal is to pass as cis, not to be a passable trans woman. Meaning, I don't want people to think about how to gender me.
I'm not there but moving the needle quickly.
What is your goal on that continuum?
How do you know you are passing? Depends on what that means to you.
I converse with women innately, get the boob stare from guys, doors and elevators held, and mansplained. I have the speech patterns, intonation, pitch and pass easily on the phone, but on occasion still get the random sir or weird glance (always from a woman) once or twice a month. But I'm not where I want to be yet.
Others might be thrilled with what I described and say they pass. It comes back to what does "to pass" mean to you.