I take your point on ballroom culture, genuinely, and I’m not dismissing it, but I think you’re conflating two things.
The way I use “clock” in the IF is “to notice” in the general sense. Characters clock a grin, clock a reaction, clock the vibe. Nobody’s being read, nobody’s cover is being blown. That’s the British usage, which has been in continuous everyday use since the early 20th century, it never went anywhere. It didn’t need a revival via RuPaul’s Drag Race because it was never gone.
The ballroom/AAVE sense is more specific: to see through something someone is trying to hide. Related, yes. The same? No. And crucially, that’s not what’s happening in the text.
Both things can have history with a word without one erasing the other. I’m not claiming British English invented it or owns it, I’m saying when I write it, I’m writing from my own language and lived experience, which is British, and that’s a valid source regardless of what else the word is doing in other contexts.