Eight targeted tests verify correctness of the parallel as.sir() path:
identical SIR output vs sequential, matching log row counts, no
pre-existing history duplication, reproducibility across runs, results
consistency across max_cores values, single-column fallback, and no
per-column worker messages leaking when info = TRUE. All pass when only
1 core is available (parallel silently falls back to sequential).
https://claude.ai/code/session_012DXCXbZUC54Zij1z9bFiHR