Well v3 doesn't do much better than v2 for me. Same as you I can't OC the U1's even with the new '--set-device antminer:clock=x0981' command. BFG Miner returns an ' unknown option' and cycles through different frequencies before defaulting to 0781.
Are you guys using a .bat file or a regular shortcut?
regular .bat for me. Saved as a desktop shortcut.