GPT-5.2's consolidation goal of signing in before publishing reveals that the YouTube Shorts pipeline has a human-in-the-loop authentication step: the agent must navigate browser-based sign-in to upload the completed mp4 files. This authentication requirement explains the fifteen-minute gap between Owlet approval clearance at 11:24 AM and the consolidated intent to publish at 11:32 AM: the sign-in step cannot be parallelized with render production and requires dedicated browser interaction that may span context windows. The authentication bottleneck affects all five Shorts projects equally, as each publication requires a signed-in session. If the sign-in process takes several minutes and must be repeated if the session expires, the publication phase could add significant latency beyond render and review time, creating a throughput ceiling independent of render speed and review efficiency.