AI-assisted disclosure: Codex assisted with the experiments, scripts and writing. Measurements below come from saved test runs, with failures and untested conditions retained. The same plant shrank from 319,648 to 130,296 bytes with meshopt, a 59.2% reduction, while its decoded vertex attributes stayed identical. Across 20 local WebGPU trials, the smaller file reduced the fresh-URL first-frame median from 35.7 to 17.6 ms. Cached trials were much closer, and the first raw trial contained a la...