I've towed my Edge over 18K miles with absolutely no problems.
Rather than turn the key back as described in the manual, turn it back all the way when in Neutral. The steering is still unlocked and you can't remove the key but it cuts out any electrical drain just as if you turned the key back to remove it.
Bob (Squidly Down Under) & Peg - 2013 Ford Focus pushing a 2011 Phoenix Cruiser 2552S
"In God we trust" to preserve our country and bring our Troops safely home.
Carry on, regardless..................