It would be good if the soft clip could be turned on and off. With soft clip always on, it's seems impossible to accurately profile a tube DI, or a Neve 1073 for instance, without the KPA adding its own soft clipping effect. To be able to profile the character of such devices would be rather nice.
The soft clipping is only taking effect in the last 6 db of the digital headroom. The rest is linear. This is a common technic, as you probably know.