I think we don’t necessarily need to assume anything, but simply keep an open and critical mind towards examining anything. All frameworks are open to revision, but if there is any merit to the metaphysical we are able to discern it somehow (logically, philosophically etc if not empirically).

To clarify, by metaphysical I mean some of the medieval era logic regarding the nature of reality. Other people also use metaphysical to mean mind-independent reality (I am not criticizing this latter definition).