Example of the R² scores obtained for each hyperparameter combination of the second-stage model with R_p ∈ [0.8, 1.0) R_J, where the y-axis is the number of estimators and the x-axis is the maximum depth. The color scale represents the mean R² value across all predicted parameters, with darker colors indicating higher accuracy. The best-performing model in this grid has 1000 estimators and a maximum depth of 46, yielding an R² = 0.826.