Perhaps this is helpful for one or the other.
Most 2x12 cabinets have a parallel speaker connection in mono mode, the Kemper Kone has 4 ohms which would then mean a total impedance of 2 ohms.
Kemper recommends a minimum of 4 ohms and for a 2x12 "cabinet
I thought about how I could implement a stereo / mono-serial connection with little effort and without an additional switch.
Three 1/4 "British Style Amplifier Jacks (BJ101 or BJ102) with disconnector are required.
Here is the result: