> The model outputs are much more concise than when I try and talk to GPT-5.6 Sol about mathematics. By signalling expertise, Tao shunts the model into “talking-to-mathematicians”

Maybe, but FWIW my first thought when I skimmed Tao's session was that he probably has a personal system prompt requesting this style.

E.g. even if you get it into "talking to an expert" mode I've found AI waffling through filler like "given your background in Linux kernel engineering, I'll skip the surface level and go straight to the technical meat". You do have to explicitly tell them if you don't want this.