Topological Decoherence and Relational Coarsening in Chern-Simons Boundary Cosmology: Derivation, Obstructions, and Open Problems

We derive the post-degeneracy dynamics of a (2+1)D SL(2,C) Chern-Simons boundary theory emerging from degenerate disformal scalar-tensor gravity. The complex level k_eff = s + it generates an exponential topological decoherence filter that selects minimal-volume hyperbolic geometries. Honest derivation of domain coarsening yields exponent n = 1/3 (Ostwald ripening under volume conservation); the observational exponent 2/3 requires a network sparsity hypothesis (R ~ L^2) formulated as an open conjecture. A Spin-TQFT path toward Majorana neutrino mass from surgery holonomy is sketched, with the SL(2,C) symmetry obstruction explicitly identified. Five open problems are enumerated. Builds on the No-Go Theorem (DOI: 10.5281/zenodo.18866200) and CS Boundary Completion (DOI: 10.5281/zenodo.18894178).