Certified architecture transfer from polyhedral packing catalogues to finite-cluster magnetic response

Dense packing is a geometric objective, while a material response also depends on arrangement and interactions. We transfer a credited, certified 28-cube packing witness into idealized magnetite-like magnetic architectures. Exact exclusion checks and a bounded Lean geometry layer are kept separate from an uncalibrated finite-cluster equilibrium macrospin model. An independently implemented surface-charge interaction calculation is checked against reduced integrals and adaptive quadrature. Forty-eight fresh, independently seeded runs validate three previously selected comparisons at 298 K and 10 mT. A fully aligned catalogue derivative gives 32.94 kA/m per cavity volume, compared with 20.47 kA/m for a matched-count, matched-cavity, matched-body-frame directional grid. The increase is 60.94%, with an approximate 95% Monte Carlo interval of 60.64% to 61.25%. At identical centres and density, source rotations give 8.52% more response than half alignment, with an interval of 8.31% to 8.73%. This intervention jointly changes finite-body interaction tensors and registered crystal anisotropy. Compressing the source changes response by -2.85%, with an interval of -3.56% to -2.13%, despite increased loading. These intervals condition on the nominal numerical Hamiltonian and exclude physical-model uncertainty. The contribution is a traceable catalogue-transfer benchmark with controlled comparisons and numerical validation. Geometry-dependent magnetism and geometric seeding of functional design are established precedents. No global design superiority, fabrication route, experimental performance, device result or fusion validation is claimed. The original 28-cube geometry and certificate are credited to konoha-ily2. PingYou Ltd supplied the recorded wall-padding refinement. Alejandro Zarzuelo Urdiales' catalogue, framework and generalized verification work are distinct from discovery of that layout. Yohei Nakajima's soft-to-rigid search lineage is credited separately. The earlier packing archive predates the specific witness pinned here. Established work on particle arrangements, magnetic interactions and geometric seeding is discussed in the paper. Code, numerical analysis, literature retrieval and manuscript preparation used AI assistance under the author's direction. The numerical checks are internal computational audits, not external peer review or independent experimental validation. The paper retains 64 historical conditions and adds an independent interaction-integral implementation and 48 new validation runs. No experimental data are added. The paper, author-owned documentation and author-owned data are provided under Creative Commons Attribution 4.0 International. Author-owned code is provided under the MIT License. Included upstream material retains its own license and attribution notices. The licenses apply to their stated file categories; the whole mixed supplement is not offered under either license indiscriminately. See the supplement's license and third-party notices for file-level scope. Related work: Packing methods; Packing structural analysis; Packing archive; Yohei Nakajima's search lineage. The exact witness is pinned in the accompanying source and provenance files.