Why on earth would you want to push fuel in the wrong direction up a fuel line when it can go straight to the engine?
Ferry fuel systems run the ragged edge of "should be approved", but there is no formal design requirement. to approve to. There is written guidance material though, which I use when evaluating these systems for flight permit acceptance. Even those documents are flawed, in my opinion, so I try to take the best from all. I am a really big Turtle Pac fan, and evaluated these systems many times.
It is very preferable to not have ferry fuel take a short cut to the engine. Whenever possible, it is flowed into the vent space of a fuel tank. By doing this, it is assured that any air bubbles trapped in the ferry fuel will release into the tank vent space, rather than be forced down a fuel line into the engine(s). And as ferry tanks typically do not have sumps, any water or contamination can be handled by the tank's sump, and sump drain system, rather than bypassing it to the engine, and causing a fuel flow interruption.
Experienced ferry pilots and organizations know all this, which is one of the very good reason to ferry aircraft with competent crews. Things still go wrong, and this is certainly not the first aircraft to splash, carrying unusable ferry fuel into the ocean with it. All we can do is our best...
Honestly, if I had to make a forced landing in the open ocean, and I had a huge ship which was expecting me, and co-operating in my recovery in advance of my landing, I'd be asking for a for a turn, and land/ditch in the lee. See this video, 2:30 in....