Payload mixes ANSI 256/truecolor, CJK, boxdraw and Powerline lines; timing happens inside the session (stopwatch around cmd /c type) so only PTY-consumption speed is measured. Commands are injected via AttachConsole + WriteConsoleInputW - no window focus involved - and the window is made topmost without activation so both shells actually render (the legacy renderer skips frames when fully occluded). First results: gpui-lab within 3.6 pct of winit-old throughput (21.8s vs 21.1s per 50MB) at 28 pct less memory; G1 threshold set at 90 pct on an equal grid. Also caught a real engine bug: the system-conhost ConPTY fallback (no sideloaded OpenConsole/conpty.dll pair) stalls completely under sustained output; fix scheduled in P2.
kuddev