So from my understanding, this is a safety issue. If for some reason the engine stops then it kills the fuel pump as well. In the event of a wreck you might not have your senses about you to stop pumping gas on an engine fire or something else bad going on. It seems there would be more situations where you'd lose oil pressure and want the fuel to stop rather than losing fuel pressure and wanting the fuel to stop.

Not that I've done this mod just yet, I am waiting on a couple parts, but I actually did have a friend who had an old 240z and that thing burnt to a cinder because he had a rear mount battery and electric fuel pump. Engine caught on fire and it basically just emptied the entire gas tank in to the fire because that was still operational.

I'm not trying to speak on behalf of pennyman or anyone else so I'll definitely let them chime in about that.

That is true about the lines emptying, but pennyman says he's been running this setup for a good long while. I wager he can attest to that aspect of it.