The methodology of getting to MDA may have 'evolved', but it is STILL a hard floor - unlike a DA, you do NOT go below it unless you have the required visual references. It is not the altitude at which you initiate the MAP.
No, it depends -- many operators in US / Canada have approved op specs to treat MDA as DA when performing SCDA approaches. Approval is granted to dip below the MDA floor during a missed approach.