With the CDA technique, you do not level off at the MDA and fly towards the MAPt before initiating a GA.
Depends entirely on company SOPs. There is nothing stopping anybody flying a CD NPA, even from a database, levelling at the MDA, proceeding to the Mapt and then executing the missed approach.
The 50ft extra is for those who wish to do the approach like an ILS ie treat the "minimum" as a DA.