The SYH per-request page_inverse migration fixes bs>1 cache contamination, but the conflict resolution made several helper/reference paths require explicit request ids and broke existing unit coverage. This keeps production bs>1 callers on explicit req-id routing while allowing bs=1/reference helpers to infer or default request ids without reintroducing the hot-path batch-global inverse.
Constraint: Runtime bs>1 materialize paths must route through per-request page_inverse rows to avoid cross-request KV aliasing.
Constraint: The remote test container may still have single-row tai-kernel materialize helpers while production bs>1 requires the new req-id ABI.
Rejected: Revert to batch-global page_inverse | it is the GSM8K cache-hit corruption root cause.
Rejected: Update tests only | the helper API is still useful for bs=1/reference callers and py-level regression coverage.
Confidence: medium
Scope-risk: moderate
Directive: Do not remove explicit loc_req_id/current_req_id from production bs>1 call sites; default inference is for legacy/reference use only.
Tested: Local py_compile for cp_shared_kv_runtime.py and nsa_indexer.py.
Tested: Remote container py_compile for cp_shared_kv_runtime.py.
Tested: Remote container pytest: test/registered/unit/mem_cache/test_cp_shared_kv_runtime.py test/registered/unit/layers/test_nsa_cp_utils.py test/registered/unit/mem_cache/test_cp_shared_kv_layout.py => 263 passed, 5 warnings, 2 subtests passed.
Not-tested: Full ETE GSM8K/cache-hit run after SYH pick.
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