OOHH!
Looks like I hit the right button!
OK, my take. I hear a lot of EC's complaining about putting a sing recpt. AND GFI protection for sump pumps. As Greg stated, I don't think there is that exception. I wish there was.
As for trans (wall warts) as you call them. (Don't think I ever heard that term.) I like the idea of the duplex with the dead top part because the wall wart is secure. I have also seen them mounted up high so that GFI protection is not required. Using a tie wrap for the wart could have a problem. Sometimes those wraps do break.
