Proximity and coherence bounds for heterocrystalline superconducting devices

A high parent transition temperature does not by itself ensure a coherent topological superconducting device. We formulate a computational benchmark for heterocrystalline chimeric technology that separates structural admissibility, proximity-induced band topology and network phase stiffness. A frequency-dependent superconducting self-energy yields a finite coupling window, while an exact weighted-network construction shows that complete connectivity can coexist with arbitrarily small stiffness. Selecting the interface coupling on 256 synthetic process draws and evaluating on 1,024 independent draws raises the probability of satisfying a 75 mK screening budget from 66.9% to 82.5%. The prescribed 90% reliability target remains unmet. A criterion-resolved survey includes AI-assisted discoveries Zr₃ScRe₈ and HfZrRe₄, without equating their bulk transition temperatures to device gaps. The results establish a reproducible method for rejecting insufficient design criteria; they do not predict material-specific transition temperatures, room-temperature superconductivity or qubit coherence times.