Well, the 200' is above the helo deck...and the designs take into account the known obstacles, and some accounting for transitory obstacles. It is unlikely, unless you have a LATS system or a GBAS, that you will get to the 200' mins, but 250' is supported by the criteria and the MOS. and SOAP still has the offsets which cause the CFITs.
Where does all that data come from, the obstacles, MDA and required offsets, location of the hold pattern and obstacle clearance?
What about departures, and the land based destination?
One other issue, I believe this system can only be used when the platform is at least 200nm from land.
CASA/ASA arent going to let this system be used for the land based destinations.