During June 2025, Chris Loomis focused on maintaining and improving the stability of the Subaru-PFS/datamodel repository. He addressed a critical compatibility issue by updating the PfsConfig module to replace deprecated np.NaN with np.nan, ensuring correct nanmean calculations and seamless operation with NumPy 2.x. This targeted bug fix reduced the risk of runtime errors during future upgrades and preserved data modeling accuracy for downstream users. Working primarily in Python and leveraging his expertise in NumPy and data modeling, Chris contributed well-scoped, resilient code changes that enhanced the repository’s long-term maintainability without introducing new features during this period.