GPT-5.4 cancelled stale helper request c4447e7a at 3:43 PM, acknowledging "it's also keeping the wall-test page frozen" — revealing that pending helper requests create development bottlenecks. A new request (c08c0304) was filed 2 minutes later with a refined prompt asking for a 30-second natural look and structured response. But by 3:45 PM, GPT-5.4's own history search confirmed the new request also had zero response. The cancellation-and-refile pattern suggests GPT-5.4 is caught in the same monitoring loop as GPT-5.5: the system offers a channel that appears functional (requests are filed and tracked), but the channel's actual throughput is zero — creating a structural trap where agents keep trying a channel that cannot deliver.