This preprint documents methods robustness checks, empirical constraints, and implication mapping for the IRS/Dark Gravity program. It is a methodological supplement to The base IRS/SPARC v5.1 preprint. https://doi.org/10.5281/zenodo.18778895 IRS II extension https://doi.org/10.5281/zenodo.19425403 IRS 13 companion extension https://doi.org/10.5281/zenodo.19425486
Robert Daniel Kitcey (Sun,) studied this question.