Folks,
MDA is not a DH.
We set the MDA in the AltSel and the PNF calls "100 above" as a warning and the PF levels off at or above the MDA while the PNF looks for the required visual reference.
A missed approach (depending upon the circumstances) is commenced no later than the Missed Approach point from not less than MDA.
This process will support continued approaches for circling or a missed approach crossing the company SOP stabilised approach VASI limit if continuing is pointless. It respects MDA as a hard limit in either case.
While we prefer a constant descent angle approach, we plan our NPA profiles to hit the MDA a bit below the normal glideslope to allow for commencement of level-off without immediately exceeding our VASI slope limit for landing, just in case it is a visibility issue more than a cloudbase issue. This process satisfies our CFIT risk management strategy.
Stay Alive,