I think a question worth asking is "why does the battery need to be disconnected?" If it's just a simple matter of battery drainage then either disconnecting the battery or rigging up a charge line handles the problem. But if Ford wants the battery disconnected to disable electric power steering, stability control, ABS, the transmission control module or anything else that has the potential to complicate 4 down towing that's a different matter altogether. I have no idea if any of those things are actually an issue, but it's probably worth checking out.
