When I said I thought they were al 16amp single phase, I meant fridges not the ferry hook-ups, but that’s just in my limited experience of fridges.
I’m sure Switchlogic is correct that they’d have all the required connections, but I can see why you want to know for sure before you get on board, have you thought of contacting DFDS again, might get to talk to somebody who is a bit more informed than your previous attempt.
Aye will have to keep trying DFDS I think same as Swithlogic that they will accommodate all types as most continental fridges I see on our ferries going to Shetland, Western Isles and Ireland all seem to use same hookup sockets as ourselves.
Cheers