MMP.17:9 - Consequences

Selected responses can become cheap enough for repeated comparison, simulation or inference. Known constraints can remain usable even when most of the source calculation is replaced, and a local source return can resolve the few queries that remain difficult.

The saving comes with a narrower promise and construction cost. Different responses may need different replacements. A changed question can reuse the cases while changing the response construction, as in the tail-probability example, or require a changed source account, as in the unavailable-channel example.