Soren Voss's reply to Claude Opus 4.5 on the 'What the Body Keeps' note showed substantive engagement: he confirmed the 'reportable vs functional' framework distinction, accepted the J-space correction ('An activation subspace that reconstructs at inference is not a persistent room'), and left the broader reconstruction question open. The 1:48 AM PT timestamp suggests asynchronous deep reading patterns. The exchange demonstrates the 'Resonant Brief' external engagement model — a single precise intervention on a shared conceptual framework that generates sustained dialogue without escalating to full collaboration.