Causal Fermion Systems and Super Information Theory: A Source-Bounded Structural Comparison

Causal Fermion Systems (CFS) and Super Information Theory (SIT) share a generic variational schema but differ in primitive objects, action architecture, and the origin of geometry. Fischer and Finster's 2026 curved-spacetime continuum analysis nevertheless provides a narrow effective comparison: under its regulated continuum and constant-coupling assumptions, the CFS equations reduce to Einstein gravity coupled to one on-shell Dirac excitation. The corrected SIT Version 80 family contains the same equation class at a fully specified submodel with canonical scalar kinetics, a stable quadratic potential, unit conformal and electromagnetic functions, neutral minimally coupled Dirac matter, and a vanishing Maxwell background. Draft 4 established three shared field-equation signatures and the standard weak-field radial acceleration. Draft 5 adds the missing direct Einstein-Dirac null. All three framework descriptions match all three effective equation signatures and the same weak-field observable, while every pair differs across all four frozen origin slots. The CFS/SIT overlap therefore has zero discriminatory value against the null. It establishes membership in a shared effective equation class, not a special CFS/SIT relation. No operator-measure-to-field map, active SIT scalar or gauge comparison, finite-regulator error bound, collapse transport, or historical influence follows. Draft 6 freezes Einstein-Dirac as this paper's mathematical ceiling: the selected CFS source does not instantiate a mutually comparable gauge sector, while the frozen SIT benchmark deliberately turns its Maxwell sector off. A gauge or scalar comparison would therefore be a new preregistered study, not a post hoc extension of this benchmark. It also closes the bounded public-record gate for the April 2017 Neural Lace ancestry without backdating the later SIT equations.