Correct on the embedded relays and the operation, I've seen the pics of those internals. I've also got the vehicle schematics, and I've noticed that they keep the particulars to that SJB proprietary and NOT in the fuggin schematics.
I was out buying parts yesterday, so while at both a Ford dealer and another Ford parts supplier I asked them to look into this. Yes, 2007 was a unique SJB and an 04 won't work. 04 - 06 *should* be the same, sans a final flash/programming at a Ford dealer. Yes, it's a dealer programming visit since they are using a piece of equipment that the public doesn't own (or doesn't want to pay to own) and the SJB flashes, well, guess who keeps the key to the gate on that one?
So the sucky thing is, and I figured this out like back in 2005, if you ever have a problem with the SJB, like say it for whatever reason fails, maybe a timer sticks on, you're pretty much forced to see the dealer for that flash. The only alternative would *probably* be if you could find a junkyard vehicle with identical options or maybe very close to yours (gotta think about the differences and potential consequences) and prey that the part numbers were exactly the same. Which get's to back the use of the word *should* in the last paragraph.