Not to derail the thread, but I happen to have a copy of the The Bicycle Wheel next to my bed.
"Although [headless or "zig-zag" spokes] are easier to replace when they break next to the freewheel, and flat spokes of this type do not require slotted flanges, the cost of getting rid of the spoke head is that these spokes tend to squirm their way out of their flanges under high tension. If tension is kept low to avoid this weakness, wheel strength is compromised" -Jobst Brandt.

Although those aren't the zig-zag variety, I still don't think I'd trust the strength of the bend vs. a traditional head. And I don't see how they'd allow you to thread them backward unless all of the spokes left the hub from the inside of the flange which would only allow you to do radial lacing which requires very high tension which brings us back to the squirming problem.
*deep breath*

so...yeah...