At matched bits, the downstream winner between two codes flips when you change the consumer — while reconstruction error says they're identical. 12-domain study, pre-registered, negative results included` [R]

TL;DR. At a matched bit budget, a code that preserves what the downstream consumer is sensitive to can beat a reconstruction-optimal code on the task while losing to it on reconstruction. Hold everything fixed and swap the consumer, and the winner flips. We tested this under sealed pre-registrations (predictions + pass/fail bars committed publicly before each run) across 12 domains. Confirmations and failures both published; the failure