Status: OUT
Module isolation limits the blast radius of compounding safety and correctness gaps: because modules are standalone artifacts with module-local error boundaries, temporal-boundary risks (TOCTOU, atomicity) compound within a module but cannot cascade across modules — but only if module boundaries are truly independent with no cross-module dependencies.
Module isolation contains compounding gaps within module boundaries, but the stock exchange's cross-module import of the message queue breaches containment and could let gaps in one module affect another's correctness
Depends on (SL): module-isolation-is-pedagogical-and-architectural, safety-and-correctness-gaps-compound
Unless: dmq-reused-by-stock-exchange