AutoMapper after version 4.2 requires that you hand in your own version of IMapper for Mapper and is going to want more verbose code in general going forward from that divide?

Well no, perhaps IMapper hand-ins are not required after all. jbogard suggests "5.0 is just Mapper.Initialize still. I didn't kill the static stuff, just Mapper.CreateMap" and moreover "Mapper.Initialize. There's a lambda there you add your CreateMap to. All config done once at startup"