The worker no longer copies rows when an array cannot grow in place. It reserves a zeroed region, returns the staged descriptor with a commit flag, and queues every other request until the main thread (the only writer) has copied the old bytes and sent commit-rows. Writes that raced the old worker-side copy were lost; lights in the glTF viewer regularly ended up at the origin because of it. Amp-Thread-ID: https://ampcode.com/threads/T-01a0b2dd-db32-712d-99ce-12ce4a86d979 Co-authored-by: Heaust Azure <heaust.azure@gmail.com>