Kemper Volume Pedal( Mark Knopfler Style )

that graph look much closer to a linear pot used in expression pedals than a log pot used in volume pedals. The Kemper takes the linear input from the exp and applies a conversion to it to make it produce a log curve (most people prefer this) when set as a volume pedal. You might be able to get a more linear curve by using Morph to control a boost pedal in front f the amp or the amp gain value rather than setting it as a volume pedal. I haven’t tried this personally as the last thing I want from a volume pedal is a linear taper but its worth experimenting yourself.