I voted “Level 4: proficient”. Pretty solid understanding of the technical underpinnings, perhaps an expert in some subareas, advanced beginner or competent in some other areas. I know a bunch about some things, know where to look up some other things or who to ask, and yet still feel like there is always another thing I’m ignorant about in another aspect of the space.
Bitcoin is a bit too broad to have “deep tacit understanding” across all of it in only a bit over a decade. ;)