Do all TS808/TS9s and their clones sound identical, do all JCM800s sound identical when recorded, how about identical cabinets with the same speakers, do they all sound identical when mic'd and recorded?
So what's the point of this discussion?
This has been the substance of most of my comments on the subject.
I would gander a guess that most of us here have a rich history of high end tube amps. Anyone with that history who says that the tone of their tube amp rigs did not have consistency issues over time, re-tubing, temperature, time after startup, mic placement, etc, etc, is simply incorrect (or just has a amorous version of those memories).
There are differences. Dead stop. No one here is saying that there are not.
The differences are quite minuscule though, and the Kemper is dead-nuts-on exactly the same tone gig after gig after gig. That was never the case for my tube amps. YMMV.