The only danger I see in the rotary knob UI is when it comes to the Master Volume. I have used a PC editor on an other device, which used rotary knobs in the GUI to mirror the physical knobs on the hardware -- and I noticed that the mouse/cursor interaction with the GUI representation of the rotary knob can be very imprecise, or react in unexpected ways.
Normally, if you are just changing an effect parameter this is not much of an issue. However, I could definitely see a major area of concern when this comes to adjusting the Master Volume / Output Volume. I could foresee the possibility of accidentally going from low volume to SPEAKER BLOW-OUT levels, particularly on the powered KPA, in the blink of an eye, by the unintended click or movement of the mouse/cursor.