In JMP Pro I can get the Root Average Square Error (RASE) for In Bag and Out of Bag trees. Using a by group, I can then compare the ratios to see if the model is similarly predictive between groups.
In the case you described, the next step after Predictor Screening is to use the strongest predictors in a regression model (Fit Model) to determine if the predictors' coefficients are significant.
JMP Systems Engineer, Health and Life Sciences (Pharma)