You are all probably following the thread on TB, but if not, it appears that the NAMM model has been left with a Berg dealer who has written that it will happily drive 2 x 4ohm cabs
"The minimum factory is 4ohm. If you dig into the menu there is an option for 2.67 and 2ohm as well. I have personally run it on the 2ohm setting with 2 (4ohm) CN212 cabinets and I can honestly say it may be one of the best sounding bass rigs."