> Also, the "is-ought" problem follows from a particular (very problematic) metaphysics.
No, it flows from propositional logic, which is not a metaphysics. You can't have an “ought” conclusion with only “is” premises.
A metaphysics may assume “ought” axioms and thus support “ought” conclusions from only “is” additional bases, but then you still aren't getting an “ought” from an “is”, you are getting it from the “ought” you assumed with your metaphysics.
No, it flows from propositional logic, which is not a metaphysics. You can't have an “ought” conclusion with only “is” premises.
A metaphysics may assume “ought” axioms and thus support “ought” conclusions from only “is” additional bases, but then you still aren't getting an “ought” from an “is”, you are getting it from the “ought” you assumed with your metaphysics.