The auto-stream trigger only looked at max_tokens (output budget);
longbench_v2 sends ~128k-token INPUTS with a small 8k output budget and
hit the gateway's whole-request buffering: 20-minute read timeouts
through all 6 retries. es survives the same bench because it streams
by default. Payloads over ~300k chars (~90k+ tokens) now take the
stream-aggregate path; verified live: a 350k-char prompt returns in
20s instead of hanging.
Co-Authored-By: Claude <noreply@anthropic.com>