Thermo IV established the exact interpolation family q = 1 + 1/K and listed independently extracting K from dynamics as its hardest testable prediction. This paper realizes that prediction for the first time on the Brusselator chemical oscillator. The central finding: in a continuous-time oscillator, K is not the one-lag effective depth m_eff(τ) — which diverges as 1/τ — but the channel-normalized winding ratio K_dyn = T/(n_ch · τ_dec), where T is the oscillation period, τ_dec is the radial decay time, and n_ch = 2 is the forward/reset channel count. The Tsallis q is predicted as q = 1 + n_ch · τ_dec / T, a zero-free-parameter formula requiring only two macroscopic timescales from the autocorrelation function. Across b = 2.2–5.0 (seven points), MAE = 0.022 with maximum |Δq| = 0.068, outperforming fixed-τ methods which collapse at extreme parameters. Two negative results sharpen Thermo IV's open problem 2: (1) m_eff(τ) ∝ 1/τ is a representation effect; (2) the inverse participation ratio K_part = 1/Σw² fails because ACF mode weights are not microscopic shielding-layer weights at finite βE. Part of the ZFCρ / Self-as-an-End (SAE) research program. Keywords Tsallis statistics; q-exponential; non-equilibrium thermodynamics; chemical oscillator; Brusselator; autocorrelation function; winding ratio; channel-averaged shielding; nonextensive statistical mechanics; SAE; ZFCρ Related Identifiers IsPartOf: ZFCρ Thermodynamics Series References: 10.5281/zenodo.19605664 (Thermo IV) References: 10.5281/zenodo.19597684 (Thermo III) References: 10.5281/zenodo.19511064 (Thermo II) References: 10.5281/zenodo.19310282 (Thermo I) License Creative Commons Attribution 4.0 International (CC BY 4.0) Version v1.0 Language English (with Chinese companion version) Subjects Statistical mechanics Nonlinear dynamics Chemical kinetics Mathematical physics Notes Fifth paper in the ZFCρ Thermodynamics sub-series. Companion Chinese version: sae-thermo-V-cn-draft-v2.md Project website: https://self-as-an-end.net