Classic multiplanner obeys replanningData.shouldCache while the deferred multiplanner ignores it. "NeverCache" is passed when the replanned plan reaches a memory limit, so there's slightly different behavior there.

https://github.com/10gen/mongo/blob/d6fe6d55f4999d00c13963ca20258d5c72b5ebd2/src/mongo/db/exec/runtime_planners/classic_runtime_planner/multi_planner.cpp#L17-L19

https://github.com/10gen/mongo/blob/d6fe6d55f4999d00c13963ca20258d5c72b5ebd2/src/mongo/db/exec/runtime_planners/exec_deferred_engine_choice_runtime_planner/multi_planner.cpp#L17-L22