CommonMC/src/SelectRecoMC_module.cc extracts the subset of low-level data (hits) associated with high-level reconstructed objects (tracks, calorimeter clusters, ...). This greatly reduces the payload while keeping content essential for monitoring, debugging, and calibration. This module also creates MC-truth based associations for tracks. These 2 use cases need to be split so that a version can be run on pure data (no MC).