Picked a tentacle-like Twin Flash arm a while back for trying out twin-flash lighting.
The problem I faced was the weight of the speedlights would cause the arms to bow.
Was just thinking if I could use an external battery pack to power the flashes, the weight on the arms would reduce considerably - and in all probability might be able to support the speedlights.
Anyone here who has tried this? I use a Canon 430 EX2