Mathematical Refutation of IP Laundering and Architecting Physical-Layer Silicon Interlocks (Part III): 3nm/2nm ASIC Post-P&R PPA Characterization, UltraScale+ HBM Hardware-in-the-Loop (HIL) Verification, CXL 3.1 / PCIe Gen6 IDE / UCIe Die-to-Die Extensions, and Human-in-Command (HIC) / SEC Rule 15c3-5 / Caremark Forensic Attestation

Following the formal mathematical refutation of syntactic Intellectual Property (IP) laundering in Part I (10.5281/zenodo.23735935) and the synthesizable SystemVerilog Register-Transfer Level (RTL) notarization of the Sovereign Physical-Layer Interlock in Part II (10.5281/zenodo.23737404), hyperscale AI operators and merchant silicon vendors face three final engineering and legal defenses: (1) commercial infeasibility due to silicon Power, Performance, and Area (PPA) overhead; (2) protocol incompatibility across disaggregated CXL 3.1 memory pools, PCIe Gen6 Integrity and Data Encryption (IDE) streams, and UCIe chiplet boundaries; and (3) lack of cycle-accurate Hardware-in-the-Loop (HIL) timing closure on production High-Bandwidth Memory (HBM) accelerators. This Part III monograph (10.5281/zenodo.23741025, revising and extending 10.5281/zenodo.23740271) resolves all three defenses simultaneously. First, we present comprehensive Post-Place-and-Route (Post-P&R) ASIC characterization across commercial 3nm FinFET (N3E) and 2nm Gate-All-Around (GAA / N2) foundry nodes, proving that the complete Sovereign Interlock occupies 0.0315 mm² (31,500 µm²)—representing an infinitesimal 0.0042% area overhead on a standard 750 mm² AI reticle die—while incurring 0.00% effective training throughput degradation via deterministic HBM3e pre-fetch latency hiding. Second, we report Static Timing Analysis (STA) closure and HIL validation on an AMD Virtex UltraScale+ HBM (xcvu37p-fsvh2892-2L-e / Alveo U55C) platform operating at 650 MHz, achieving a positive Worst Negative Slack of WNS = +0.142 ns and sub-cycle (< 1.538 ns) PCIe DMA zeroization upon unlicensed provenance detection. Third, we formalize the CXL 3.1 / PCIe Gen6 512-bit Flit extension (56.5 ns multi-tenant memory pool Sovereign Lock) and UCIe Die-to-Die heartbeat monitoring linked directly to the <= 2.5 mOhm GaN crowbar (PHOENIX_ROUTER). Finally, we specify a hypervisor-bypassing zk-STARK Remote Attestation API reading the 2,048-bit One-Time Programmable (OTP) eFuse (f_otp_latch) to enforce Human-in-Command (HIC) governance and establish incontrovertible Scienter under SEC Rule 15c3-5 and Delaware Caremark fiduciary standards. Complete Vivado XDC physical constraints and cycle-accurate SystemVerilog RTL/testbench modules are provided in Appendices A–C.