Compare exact evaluation coverage sets, not only request totals

An unchanged evaluation request count does not prove unchanged coverage. A smaller evidence encoding can make one previously oversized case eligible while a policy or provenance addition makes a different case ineligible; the total stays constant. Before claiming a regression-free optimization, compare stable scope identities (case, dimension, node or episode) and report retained, lost, and newly available sets separately. Compare request-body digests separately because intended prompt changes legitimately alter them. Also verify decoded evidence equality; never count a size-skipped check as a fixed false flag.

Applies when: Optimizing evaluator input packing or prompts under per-request evidence limits. Keywords: evaluator coverage request count regression packing evidence scope comparison