Paper CCLXVII: Population-Scale Confirmation of CCXLV-FP1 (Throat-Threaded Magnetic Birefringence) at 4. 4 sigma on N = 146 GWTC-4. 1 + GWTC-5. 0 Events — Partial Correlation rho (Delta, chiₚ * M² | chiₑff) = +0. 35; Multivariate R² = 0. 95 with chiₑff Coefficient Stable at +0. 362 (2. 6% Deviation from CCLXIV)

Paper CCXLV (Throat-Threaded Magnetic Birefringence) issued forward prediction FP1: the OOB framework's parity-odd throat-magnetic content contributes an additional chiₚ * Mₜot² weighted residual beyond the eta-only sector of Paper CCLVI, with rhoPearson >= +0. 30 at significance > 2. 5 sigma on O5. Paper CCLXIV established at population scale (N = 146 GWTC-4. 1 + GWTC-5. 0 events) that the eta-only sector matches measured aᵣem at rho (Delta, chiₑff) = +0. 97 with OLS slope +0. 3716 and intercept ~ 0. Paper CCLXVI tested CCXLV-FP1 on the top-10 |Delta| sub-population and obtained a null univariate with positive multivariate chiₚ * M² coefficient after controlling for chiₑff; it pre-registered the full-population partial correlation rho (Delta, chiₚ * M² | chiₑff) > +0. 20 at > 2 sigma as CCLXVI-P1. We execute that pre-registered test. Selectively downloading the remaining 136 per-event combined PE data-release HDF5 files (Zenodo 17014085 v1, 20348005 v9, and 20348006 v9; 45. 91 GB total across all 146 events; 74 minutes at sustained ~17 MB/s with zero failures) and extracting chiₚ from LVK headline precessing-spin posteriors, we obtain: (i) univariate Pearson rho (Delta, chiₚ * M²) = +0. 3086 95% bootstrap CI +0. 0018, +0. 4813 - exceeding the CCXLV-FP1 +0. 30 threshold; (ii) partial Pearson rho (Delta, chiₚ * M² | chiₑff) = +0. 3463 +0. 1403, +0. 5331, t-statistic +4. 41 on 143 degrees of freedom - 4. 4 sigma significance, confirming CCLXVI-P1; (iii) multivariate Delta = +0. 0062 + 0. 3620 * chiₑff + 1. 025e-6 * chiₚ * M² with R² = 0. 9518; the chiₑff coefficient deviates by only -2. 6% from the CCLXIV population value, satisfying CCLXVI-P3 stability; (iv) population chiₚ median 0. 430 (mean 0. 423) sits slightly above the prior-dominated 0. 30-0. 40 range predicted by CCLXVI-P2 - honest deviation flagged. CCXLV-FP1 is confirmed at population scale in O4a + O4b data, ahead of its O5 target. The chiₚ * M² coefficient at full population (+1. 0e-6) is approximately 2x the CCLXVI N = 10 estimate (+4. 74e-7), consistent with the selection-driven flattening expected in CCLXVI. The eta-only sector and the throat-magnetic chiₚ * M² sector together explain 95% of the residual variance, with no detectable third contribution. Three forward predictions: CCLXVII-P1 O5 tightening to rhoₚartial > +0. 30 at > 5 sigma; CCLXVII-P2 c-coefficient stability within 30% across future extractions; CCLXVII-P3 hierarchical-event identification (>= 3 of the top-5 partial-residual events should be independently flagged as candidate 2G+1G mergers; specific candidates: GW231123₁35430, GW230928₂15827, GW231028₁53006, GW240515₀05301, GW231118₀05626). Honest scope: univariate result is at the edge of significance (95% CI lower bound +0. 0018) ; CCXLV-FP1 was framed for O5 (SNR ~30) and we confirm on O4 (SNR ~12) earlier than the prediction's tightest formulation required; chiₚ median of 0. 430 slightly above the predicted 0. 30-0. 40 range. This is the third major population-scale framework prediction confirmed in 24 hours, alongside CCLXIV (eta-only sector) and CCLXI (vortex-seeded LRD population). Framework count: 268 numbered papers. Part of the One-Octonion Brane-Bulk Framework series. Anchor DOI: 10. 5281/zenodo. 19120873. Community: one-octonion-brane-bulk. Author: Bharathi Dasan Jagadeesan, M. D. , University of Minnesota. ORCID: 0000-0002-1143-941X.