Generative production fails financially in a specific way: a shot that is nearly right invites one more attempt, and one more attempt is cheap, and forty of them are not. The ceiling exists because the marginal decision is always defensible and the cumulative one never is.
It only works if it is in the pipeline rather than in a meeting. A number everybody agreed and nobody encoded is an intention. A number that stops the run and raises a decision is a control.
We set one per asset before a batch starts. When a shot reaches it, the job halts and a person decides whether to keep going, change the approach, or drop the shot.
Where should a credit ceiling be set?
At the point where a rational person would stop and reconsider the approach rather than try again. In practice that is roughly three times the expected render count for that shot type.
What should happen when a batch hits the ceiling?
The run halts and escalates to a named person. Logging a warning and continuing is not a ceiling, it is a note.