Here ln(P o eq /P o ) is the equilibrium plateau pressure at 25 • C with reference P o = 1 bar, and ∆H d and ∆S d are the desorption enthalpy and entropy, respectively. How- ) near ambient. To target low-stability hydrides for potential use as a high-pressure compression material, we adopt a simple heuristic strategy rather than relying on quantitative ML prediction accuracy in these data-limited regimes. We first identify a metal hydride from the literature that already shows promise for high-pressure H 2 compression based on an appropriately low hydride stability, low hysteresis, and relatively flat PCT plateau, but whose thermodynamic stability is still not optimal or does not have a validated PCT measurement up to 1000 bar. Then, we select a substitution strategy that is consistent with the SHAP analysis (Figure ) design rules for tuning ln(P o eq /P o ) (or ∆H), i.e., the compositional features most likely to increase plateau pressure (by decreasing ∆H) are reducing νpa , increasing χ decreasing rc , and increasing SG#. For the set of transition metal elements E, Table shows the subset of elements e that can be substituted for some target e ′ , while satisfying an increasing number of SHAP design rules for increasing ln(P o eq /P o ). Based on these simple heuristics, Co and Ni-substitution for Mn, Cr, or Fe tend to simultaneously satisfy the most design criteria, while substitution by Co instead of Ni will yield the largest decrease in ν pa .