Preregistered Evaluation of System-Level Burden Tradeoff in Upstream Conditioning Architectures

This preregistration defines a confirmatory evaluation of whether an upstream conditioning architecture in surface-code quantum error correction exhibits a favorable system-level burden tradeoff under fixed-budget constraints. The study introduces no new simulations, no new observables, and no decoder-internal instrumentation. Instead, it analyzes only preregistered artifacts from the frozen Megasweep v4 design, using architecture-level, decoder-facing quantities to compare reductions in downstream burden against corresponding upstream conditioning burden. The purpose of this component is narrower than the earlier architecture and heterogeneity components. Components A and B evaluated whether an abstract upstream intervention produces a real, reproducible structural footprint and whether differential conditioning outperforms uniform allocation under matched-budget conditions. Component C extends that framework by evaluating whether the observed downstream burden relief remains favorable when considered as a system-level tradeoff within the preregistered operating regime. All metrics, normalization rules, operating-regime definitions, and closure criteria are specified in advance under the same Clean Room governance used throughout the project. The analysis is restricted to frozen datasets, frozen design conditions, and exposed observables only. No decoder-internal telemetry, hardware-specific latency claims, FPGA implementation claims, or mechanism-level interpretations are used. This component is intended to support statements about system-level burden tradeoffs at the architecture level while preserving the project’s interpretation ceiling and implementation-agnostic disclosure posture. Expected outputs include a preregistered figure showing the net-efficiency metric across ratio levels and distances, together with predefined sensitivity views under alternative upstream normalizations. Confirmatory outcomes are defined in advance: whether net efficiency remains positive in the frozen primary operating regimes, whether downstream burden relief is accompanied by non-adverse directional change in the exposed structural cross-check, and whether the sign and within-distance ordering of the burden-tradeoff result remain stable under predefined sensitivity analyses. More broadly, this component is designed to provide a governed, reproducible evaluation of system-level burden tradeoff without exceeding the scope of the preregistered architecture-level evidence.