Catellix This document specifies the MVPS Performance-Security Coupling Profile, a Profile-of-Profiles binding three previously specified profiles into a single deployable contract: o MVPS Coherent-Witness Trust (CWT) [I-D.melegassi-santos-ippm-mvps-cwt], o Coherence-BFD [I-D.melegassi-coherence-bfd], and o MVPS DDoS Resilience [I-D.melegassi-mvps-ddos-resilience]. Each composed profile proves its own theorems and reports its own measured numbers under its own scale assumption. When deployed together, those scale assumptions diverge by 1-2 orders of magnitude and create five composition holes: a numerical cost- rescaling gap, a double replay-counter rule, an under-specified key-derivation step, an insider verification-DoS gap, and a joint Byzantine-at-limit / collector-split-view gap. This profile closes all five with three theorems: T-JCOST-1. Closed-form joint broker CPU cost as a function of (N, T_tick, q, bundle_period); two-path decomposition (CWT path + Coherence-BFD path) avoids double-count; numerical receipt at four scale points. T-VDOS-1. Per-vantage rate-limit at NIC/XDP fast-path bounds the attacked-broker CPU by a near-constant factor (rate_limit_factor + flood * c_xdp / c_path) instead of the linear blow-up of the unprotected case. T-RC-1. Acceptance is the AND of the BFD sequence rule and the CWT counter rule; rejection cases are enumerated. A normative HKDF info-string for cross-profile key separation closes the under-specification of CWT Section 13. The dual-mode aggregation values (D_minimax, D_max) defined in DDoS-Resilience Section 7.2 are bound INTO the cosigned checkpoint of CWT Section 8.2, closing the joint Byzantine + split-view gap. The profile inherits the full v4.0 theorem catalogue and is conformant to the MVPS Architecture Invariance Theorem [I-D.melegassi-iab-mvps-architecture]. Full proofs are recorded in [PERFSEC-PROOF]; numerical receipts are in evidence/perfsec_joint_cost_receipt.json and evidence/perfsec_verification_dos_receipt.json; the validator scripts/validate_perfsec_coupling.py returns 12/12 PASS.