I helped design/spec the 66 with Tom @ COG (I have the prototype) so always happy to see when people are interested .
Basically the Knightfall is too separate channels, where you set the clipping, gain and volume on each channel, you then switch between the channels. The EQ and blend is then global.
The Dual Knightfall is a bit different, no blend, and effectively two Knightfalls in one box, where I kicking in the second runs one into the other.....or run each one on its own
Si