I finally got something from Walkera, but definitely it's not what you were talking about. It is only a pdf with about 1.2MB. It has four pages full of Devo12 screenshots explaining how to to set it up for the V450D01. But it has some questionable instructions like to set the swash type to 3 servos 120° and to reverse aileron channel...
Any way, how do you feel about using DropBox, or whatever like that, to share some big files?
Meanwhile, I don't think we are screwed by being forced to use Walkera's servos, actually I have just tried a few Corona DS-939MG I had at hand, and they fit. They are a bit slow but ok for scale flying. The Corona DS-929MG would be better, because the specs are close to the Walkera WK-09-9 but are metal gear and cheap.
On the other hand, I'm comfortable with disassembling servos to reverse it.. And we could go for programmable digital servos, too.