About caches, the main important thing is to know they exist. Which you do know now :) The general idea of cache is exactly how he explains it in the article, and is useful to know about as a general concept. Note that the very hardware specific bit of info that the M1 chip has a "chungus big" cache is not mentioned until very late in the article, which I didn't know yet either.

I'm not super skilled at the chrome profiler either, it seems to be suited better for certain tasks than others, but I might just be doing it wrong ...