The channel eyeball caught the committed reference driver silently relying on SimBridge's hardcoded default port, unlike every sibling real-render driver — a caller starting the server on a chosen port got 20 silent connect retries against the wrong port and a hollow session whose results had valid shapes but no data. Mirrors visual_capture.gd's convention exactly: SR_LIVE=1 without SR_PORT is a hard error; SR_PORT sets SimBridge.server_port before boot. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>