I was a Bogner Shiva user for years and yes you can use it as you describe. It sounds great that way. But... I wouldn't bother, personally. The Shiva is a heavy animal and in order to get the power amp tubes cooking you would have to get the volume right up. I highly prefer just a great Shiva profile.
Similar with me. I had (still have in a cupboard) a Mesa Triaxis and matching 2:ninety stereo poweramp. I could easily use the 2:ninety with the KPA but to my mind it just isn’t worth the effort. That thing is a beast and weighs about 3.5 tons 😆 Like all valve power amps it sounds best when run at a volume which is way too loud for most things so I would take a profile of this rig over my real rig every day of the week.