This manuscript presents a two‑mode ringdown analysis of GW190521, demonstrating that single‑mode 220 fits are unstable across start times and cannot capture the relaxation structure of the event. Including both the 220 and 210 fundamental modes stabilizes the inference and yields remnant parameters consistent with NRSur7dq4. A 75 Hz frequency cut isolates the physically meaningful low‑frequency branch and removes a high‑frequency degeneracy that contaminates early‑time fits. On this branch, both modes exhibit damping times of order 10 ms, consistent with the GR prediction for a 142 M⊙, a ≈ 0.7 remnant.We compare this timescale with the relaxation timescale implied by a parameter‑free induced‑metric constraint and find agreement. GW190521 therefore provides a cross‑regime consistency check linking strong‑field GR ringdown to a universal relaxation law. This document is part of the broader informational‑geometric framework and the Universal Relaxation Experiment. This manuscript is part of a multi‑document sequence establishing the informational‑geometric framework and the Universal Relaxation Experiment. A formal submission to Physical Review D will occur after completion of the full architecture. Mathematical Typesetting Statement All mathematical expressions in this manuscript are presented in duplicate form.The bold Unicode expressions constitute the visually readable mathematical text.Each bold Unicode expression is followed by a LaTeX rendering in parentheses for archival precision.In cases where minor typographical differences arise between the two renderings, the LaTeX expression takes precedence as the authoritative mathematical content. Conical Source Statement This work is part of a unified research program developed across multiple volumes. Each volume stands on its own while also forming a coherent component of a larger theoretical structure. Readers encountering this volume independently are encouraged to view it as one face of a conical source: a single underlying informational‑geometric framework projecting into multiple disciplinary domains. The geometry, relaxation dynamics, induced‑metric structure, and particle‑level eigenmodes presented here all arise from the same substrate‑level principles articulated throughout the series.
Mark Edwards (Tue,) studied this question.