RE: Safety and the MOB
I believe trying to use an existing stanchion or railing as an attach point for a Lifesling or other retrieval system would subject them to sideloads that would certainly bend them over if not pull them out of the deck altogether.
Better, I think to come up with some purpose-built attach point that will let you haul someone up the side of the boat. As Skipperdude said, you don't want to be messing around with an unconscious or semi-conscious person at the swimstep with the boat pitching and rolling, which is probably what caused the person to go over in the first place.
There are a variety of davits available that would work for your purpose. Some friends of ours installed one on their sailboat for lowering and retrieving the outboard motor they use on their towed dinghy.
I see your boat has a radar arch. Perhaps, if it is strong enough, that could provide an attach point for a retrieval system down the side of the boat.