Philosophy has always been metaphysics. This will help ensure that it remains so. The scholars under Petrus Damiani struggled over factum non infectum in the 11th century: That what has happened will not "unhappen" is fundamental to all sciences.
From an extensional point of view Kant's formula 7 + 5 = 12 remains correct, but from an intensional - metaphysical point of view, it is no longer trivial.
That colours on surfaces can say something about them does not follow from meaning and confirmed long after Kant and his ontology: the conceptual inexhaustibility of intuition.
The theory of knowledge of quantum physics leads to the theory of intuition and causality.
Digression: Galileo and the constancy of time.