I am not yet on the new KAOS (busy performing, don't want to touch anything as of now) so could not experience things in person. But I've read from several, unrelated people that when they add a liquid tonestack to an existing profile the sound changes even before they touch any control.
From reading the manual this should not be the case?
The Amp Model will not color the sound at all as long as the controls remain at their original position. But once the Gain or EQ controls are moved, they will change the sound exactly as they would on the original tube amp.
OTOH, a few lines before this, it also reads
As you browse through the different amp models and channels, watch the Amp Gain change as it adapts the Amp Model to the underlying PROFILE. Much of the time, you might only perceive a slight change to the sound, if any at all.
So not sure what to expect...
Waiting for observations from Support or from those who are already using the function