I don't really agree with functioning labels for the most part with exceptions. I was diagnosed with autism when I was young so i don't remember much but it was definitely autism, not aspergers or anything else.
Most of the time I kind of skate between levels 1 and 2. When I was in school I had to have a lot of help and for several years I had to have an aid follow me from classroom to classroom, help me take notes, do work, stay focused, take me out when I got meltdowns etc. I went to public school but was in a class specifically for autistic people.
I didn't really speak to anyone except close friends and family until about 7th grade. I also had some noticeable stims but most of them were stuff like shaking my legs and biting my fingers.
These days I'm more of a 1 most of the time but I think that's because a lot of the time im functioning at my very limit. It's still obvious that I'm autistic because of the things I do. How I react to sounds and people touching me, my flat voice, lack or excess of eye contact, spacieness, stims, general incompetence, etc.
Also my stims have gotten a lot more noticable like rocking and flapping, I think this is my brains way of compensating for working so hard.