First public release of the MG-PCA-DataReduction dataset and code. Includes: Code to run a simplified 3×2pt LSST Y1-like simulated analysis Support for two data reduction approaches (Standard linear scale cuts and a Novel PCA-based data reduction method) Scripts to compute posterior chains for simulated datavectors (implemented for multiple theories: GR, f(R), nDGP, and ESS) Example configurations for running likelihood inference with different data reduction methods Known limitations: Survey specifications and covariance are hard-coded Pipeline is intended as a simplified demonstration, not a full LSST-ready implementation (limited nuisance parameter set)