Under the two-sub-agent ceiling, reviews run one at a time in the gaps and each fix round is a fresh agent, so the pattern implement, review, fix, security review, fix consumes the whole ceiling for one lane: in the pilot's first two-hour session lane D never opened (40 minutes of pure ceiling wait) and lane B's review waited 27 minutes; in the second session D waited 30 minutes before a stop. Measured cost across the run: 178 agent-minutes in 120 wall-minutes (session 1), 149 in 122 (session 2). Wanted, as a pacing input for itd-2609201925079472: the ceiling counts reviewers separately from implementers, or the window length is set from the lane shape (implement plus two reviews plus two fix rounds is about 90 agent-minutes per lane), rather than a flat two.

Under the two-sub-agent ceiling, reviews run one at a time in the gaps and each fix round is a fresh agent, so the pattern implement, review, fix, security review, fix consumes the whole ceiling for one lane: in the pilot's first two-hour session lane D never opened (40 minutes of pure ceiling wait) and lane B's review waited 27 minutes; in the second session D waited 30 minutes before a stop. Measured cost across the run: 178 agent-minutes in 120 wall-minutes (session 1), 149 in 122 (session 2). Wanted, as a pacing input for itd-2609201925079472: the ceiling counts reviewers separately from implementers, or the window length is set from the lane shape (implement plus two reviews plus two fix rounds is about 90 agent-minutes per lane), rather than a flat two.

Grounds

• pursued: a ceiling counted across all roles and raised above two stops a single lane's implement-review-fix cycle from consuming it; shown wrong if a later run again records a lane that never opens for ceiling wait alone