CD12 has not exclusions based on CRP, which as you note is a good predictor of mortality, though I do not concur that it is the strongest predictor despite circumstantial evidence.
It is difficult to appreciate your saying, essentially in the same breath that:
(We know that CD12 included ventilated patients and patient on ECMO, just not the worst ARDS with simultaneous low PaO2/FiO2 ration and high PEEP